Ripples

Temperature---Revisited

2011-12-20T12:14:00.000-06:00

In two (2) recent studies, determinations were sought as tothe effects of temperature on (1) egg development and spawn growth in Koi/Carp (Cyprinus Carpio) and (2) foraging andgrowth rate of juvenile Koi/Carp (Cyrpinuscarpio).

Itwas shown in the first study that “The present results suggest that water pH 7.5 at water temperature 26°C/79Fis best for hatchability of eggs and pH 7.39 for growth of spawn of Cyprinuscarpio at same water temperature.

(Optimal water temperature and pH fordevelopment of eggs and growth of spawn of common carp (Cyprinus carpio)

P.H.Sapkalea*, R.K. Singha & A.S. Desaia)

Thesecond study showed “Temperaturehad a significant and positive effect on the foraging and growth of juvenilecommon carp Cyprinus carpio (90–105 mm) between 16C/61F and 28C/82F …… Theseoutputs suggest an increase in foraging and growth of C. carpio according to athermal gradient that were maximal between 24C/75F and 28C/82F.

(Effects of temperature on the foragingand growth rate of juvenile common carp, Cyprinus carpio D.O. Oyugi1, J. Cucherousset2, D.J. Baker,J.R. Britton )

Comparingthe results of these two (2) studies we quickly see that the temperature of26C/79F was independently arrived at as the optimal temperature. Thistemperature is very close, though slightly lower, to what we stated in ourprevious blog post on temperature in December of 2010.

“Even though nodiscomfort (stress) is manifested between 20C/68F and 34C/93F, ideally we wantthe temperature to be close to the midpoint of this range which is27.5C/81-82F. This is well above the median temperature recommended bymany sources, but is shown to be the ideal temperature for the Carp’s (Koi’s)optimum metabolism.”

Are Pond Ionizers Safe? You be the judge.

2011-12-06T15:10:00.000-06:00

Certain manufacturers of Pond equipment decided to borrow atechnology from the Swimming Pool industry and, with maybe some minor tweaks,promote it as an exciting breakthrough in controlling Pond algae. Presentingthe IONIZER!

Through the controlled release of Copper, Zinc and Silverions into the pond’s water column, algae growth can be controlled and in manycases eliminated. This, on the surface, is great news for Pondkeepers. Nolonger is it necessary to use expensive and hard-to-correctly-measure chemicals.Just set the Ionizer to the desired level and algae disappears.

Sounds great! However, there is more to be considered than justwhat the advertisements claim. What are the other potential and likely resultsfrom use of this device that the manufacturers are not telling us?

Let’s look at some of the manufacturers’ claims as regardsIonizers.

Company#1 - “Destroys Bacteria

Kills Algae

Reduces chemical cost

Eliminates chemicalodors

Reduces maintenance

EnvironmentallyFriendly

Costs pennies permonth

Helps reduce filtration

Fish safe

Includes 2" TFitting”

Company #2 - “Safe for fish and plants

Low maintenance

Clears water withoutthe use of harsh chemicals

Easily installed inany new or existing water feature

Treats ponds up to25,000 gallons

Level ofmineralization is controlled by the LED panel

Cast mineral anodes areself-cleaning

1 year warranty”

Company#3 –“Drastically reduces pond maintenance

Crystal clear water without theuse of chemicals

Eliminates unsightly water conditions

Simple to install

Safe for fish and plants

Not toxic to animals that maydrink from the pond

Energy efficient (less than $ 1 amonth in electricity cost)

Treats ponds up to 25,000gallons”

Understandably,the first concern of a Pondkeeper is whether a product or treatment is safe forfish. All three (3) of these manufacturers declare that the (proper) use ofthis device is safe for fish. Let’s take a closer look at this claim.

AllThree (3) manufacturers include test strips for monitoring Copper levels withTwo (2) of the manufacturers recommending maximum Copper levels at 0.25 mg/Land the remaining manufacturer recommending 0.30 mg/L as the maximum level ofCopper.

Copperis a heavy metal and in low concentrations can be toxic. In addition, likeother heavy metals, such as Mercury, it is a bio-accumulate. This means thatonce it is ingested by an organism it remains in that organism for an extendedperiod of time, in many cases, for life. Any additional ingestion onlyincreases the level that is already present in the organism until eventually acertain level of toxicity is reached. For terrestrial organisms, this level isdetermined primarily by the ingestion of food and water, but for aquaticorganisms, if the Copper is in suspension as ions, it may be ingested duringthe respiration process also, as is the case with fis juvenile amphibians,certain insect larvae, true aquatic invertebrates and bacteria as well as thetarget taxa of algae. In the case of fish, it causes increased mucousproduction on the skin and the gills where it eventually interferes with therespiration process by blocking the absorption of Oxygen.

Inassessing the potential toxicity of any substance to any organism, two (2)distinct levels must be determined, acute (immediate short term) and chronic(long term). Heavy metals have long been known to play an important beneficialand cricial role in animal and plant physiology, but at levels so low that theyare undetectable by standard testing.

Considerablygreater attention has been given, in recent years, to the effect of HeavyMetals and other chemical compounds on the environment. Research is ongoing inboth the public and private sector. This research has resulted in someuniversally accepted toxicity levels as regards Heavy Metals.

Thefocus here will be on Copper. Copper, after Mercury, is the most toxic of theHeavy Metals. Copper’s toxicity is greatly influenced by water Hardness and pH.As water Hardness and ph increase, the toxicity of Copper is reduced. Here isan example of a couple of simple formulae that are used to define the acceptedlevel of Copper in fresh water.

Maximum Copper levels (in micrograms) atany time—0.094(hardness)+2 (where water Hardness is reported as mg/L CaCO3.

30 day average Copper levels (inmicrograms)—0.04 average hardness (where water Hardness is reported asmg/L CaCO3.

(Environmental Protection Division,Ministry of Environment, Government of British Columbia)

Note- There are other formulas used by different government entities worldwide, butthe final accepted levels of Copper vary by only a few micrograms.

Usingthese two (2) formulae, in water with a Hardness of 120 ppm for example, wefind the recommended Copper levels to be 13 micrograms/L at any one time and the30 day average should not exceed 5 micrograms/L Knowing that one milligram equals 1000micrograms, these results expressed in mg/L would be 0.013 mg/L and 0.05 mg/L.These results appear to be on the conservative side, but considering the factthat some aquatic organisms have a very low tolerance to Copper, these formulaeare quite appropriate.

Theseare the Metal Safe Limit levels as defined in the Textbook of Fish Health:Copper 0.014mg/l More toxic in soft water; Zinc exacerbates toxicity; Combinedboth are dangerous; Zinc 0.01mg/l Synergistic with copper; 0.15mg/l In hardWater; Cadmium 0.03mg/l; Chromium 0.10mg/l; Lead 0.01mg/l In soft Water;4.00mg/l In hard Water; Silver 0.03mg/l (mg/l is the same as ppm).

Theauthor was unable to find any scientifically set copper toxicity levels forKoi, but several anecdotal sources were found that stated that Koi begin toshow copper toxicity at 0.03 ppm along with the copper toxicity level for Koiat 0.3 ppm., which is at or extremely close to the Maximum levels suggested bythe manufacturers of these devices. It should be stressed that no scientificstudies were found that substantiated these levels. In fact, one study reportedthat Koi fry were unaffected by Copper levels of 1.00 mg/L.

Itis important, however, to know the signs and symptoms of Copper toxicity inKoi. One of the earliest effects of toomuch copper is apparent fish hypoxia, the loss of ability to use oxygen. Commonsymptoms of initial acute toxicity are fish gasping, disoriented (ataxic) atthe surface, due to copper's hemolytic (blood cell splitting) andmucus-producing effects. Copper is a proteinaceous precipitant; that is, itcauses your fish to produce more mucus. This may aid the in the suffocation orsloughing off of parasites, but also interferes with respiration through theirskin and gills.

Ofgreater concern is the previously mentioned fact that all heavy metals are bio-accumulates.This accumulation leads to immunosuppression. Fish are often observed suffering from bacterial infections for no apparentreason. Water quality is optimum butlow levels of copper and/or zinc are present. Metals are most toxic in lowalkalinity and pH. This allows for a higher concentration of metal to remaindissolved. The accumulation over time immunosuppresses the fish and allows thenormal pathogenic bacteria to gain the upper hand leading to ulceration andpossible septicemia (bacteria in the bloodstream).

Ineco-system ponds, along with the fish, the toxicity of copper to all otheraquatic organisms is of equal importance. Considerably more data is availableon the effects of copper on fresh water fauna due to the fact that they arepresent in every natural waterway and their numbers and diversity are primeindicators of the health of any aquatic eco-system.

Copperis extremely toxic to most invertebrates and the juvenile forms of mostamphibians.

“Northernleopard frogs (Rana pipiens) were exposed to environmentally relevantconcentrations of copper in water (control and 5, 25, and 100 microg/L, asCuSO4) in a static renewal system for 154 d from posthatch stage tometamorphosis. Tadpole survival, swimming performance, percent metamorphosis,time to metamorphosis, and survival during and time required for tailresorption were negatively affected in the 100-microg/L treatment.”

-Adverse effects of chronic copperexposure in larval northern leopard frogs (Rana pipiens).

ChenTH, Gross JA, Karasov WH.

Availabletoxicity data on amphibians indicate copper 96 h LC50 values calculated intadpoles ranged from 0.04 to 5.38 mg/L. Studies of other aquatic organisms show96 h LC50 values ranging from 0.06 to 6.68 mg/L.

Representativetoxicity levels for some other fresh water organisms are-

Most snails – 8 - 41 micrograms/L;Cladocerans (including Daphnia) 5 - 213 micrograms/L; Amphipods 8 - 87micrograms/L

Althoughthe Mayfly is fairly sensitive to Copper, the majority of insects that haveaquatic larval stages are tolerant, most notable Damselflies and Dragonflies,which are always expected visitors to any aquatic venue. These Odonates havethe ability to store heavy metals in their exoskeletons where it remainsharmless.

Theinhibition, reduction or elimination of any member group of the aquatic foodchain will have negative effects on the overall health of the eco-system to alesser or greater degree depending on which species are residents of thatparticular eco-system and their relative position in the food web.. Nevertheless,any negative effect on an aquatic eco-system’s food chain and/or diversity willhave deleterious effects on the entire system.

Theonly organisms that have not been discussed are the bacteria, in particular,the nitrifying bacteria. The results of studies on the toxic effects of Copperare quite surprising. Copper and Zinc appear to be the least toxic of themetals tested. Copper, at low levels, actually stimulates activity in Nitrobacter. At levels up to 0 50 mg/L the Copper ion has notoxic effecton Nitrobacter. Instead, the stimulatory effect is readily apparent......Apparently. at 0 50 mg/L Copper has not reached the cross-overpoint where a chemical shows neither stimulatory nor inhibitory effects. This,unfortunately, is not true of Nitrosomonas. Growth of Nitrosomonas is greatlyinhibited (about 60%) by Copper concentrations of 0.20 ppm.

Growth of Nitrosomonas europaea in batch and continuous culture (Skinner & Walker 1960)
Copper was also found to be one of the most toxic metals to heterotrophic bacteria in aquatic environments.
Sadly, company #1 is partially correct inclaiming that their ionizer “destroys bacteria”.

Inconclusion, based on the above data, we arrive at these facts-

-Ionizers can indeed control and, in someinstances, eliminate many species of algae.

-Within the manufacturers’ suggested range ofuse, 0 – 25/30 mg/L, neither Koi or Goldfish should exhibit any immediateeffects of Copper toxicity. It has been shown that Koi fry can tolerate levelsof 1.00 mg/L. Due to lack of any meaningful research, long term (chronic)effects are unknown.

-Copper at low levels is extremely toxic toaquatic stages of most amphibians.

-Most microorganisms exhibit toxic effects ofCopper at extremely low levels and, where mortality does not occur, the effectsare compounded in second generations.

-The effects of relatively low (.20 ppm)Copper levels on one of the main species involved in Nitrogen conversion hasthe potential to cause major problems in the form of Ammonia spikes.

Consideringthe whole picture regarding the impact that an Ionizer may have on an aquaticeco-system, this author has no intention of availing himself of its use. Thereare other effective and absolutely safe ways of controlling and/or eliminatingalgae. You, the reader, may feel differently. After all, it’s your Pond andyour fish.

Yoube the judge!

When you care enough........

2011-08-06T11:21:00.000-05:00

All Water Features support life. We know that any surface that remains wet with water will support, at the least, a microscopic biofilm composed of bacteria, archaea and algae. In decorative Water Features such as formal fountains, water walls and rock bubblers, because of aesthetic considerations, the water is usually treated with chemicals to inhibit the growth of this biofilm.

The opposite is true in Water features that are purposely constructed to support life such as a Water Garden, turtle pond, Garden Pond, etc. This biofilm growth is desired and , indeed, encouraged for it is the foundation of life. It supplies the basic mechanisms in the Nitrogen cycle as well as the Carbon cycle. The greater the surface area of this Biofilm, the more varied and larger organisms that can be supported.. Only when this surface area is large enough can a stable population of fish be sustained and thrive.. There must be enough biofilm to oxidize the Ammonia and other wastes produced by the fish and support an adequate food chain.

In Nature, this balance is a naturally occurring process. It is when we strive to construct artificial aquatic environments that some outside intervention is usually required by providing supplemental bio-conversion through the use of ‘biological filters’ and by supplemental feeding that may be needed to correct any existing food chain deficiency.

These questions arise:

Do I need ‘bio-filtration’?

If the Water Feature is strictly a Water Garden (No fish, turtles, ducks etc), supplemental bio-conversion is not needed. However, if the Water Feature is to house any of these, then additional bio-conversion is usually a definite requirement. Granted, although a feature of large enough submerged surface area may comfortably support a limited fish population, most people neither have the space or desire to dedicate a few thousand square feet of property to house a handful of fish.

What type and size of ‘bio filter’ do I need?

Type of ‘bio-filter’ is a matter of personal preference…cost, ease of maintenance and possibly aesthetics are possible considerations. Size is of greater importance only as it relates to filter media capacity which itself is dependant on the type of filter media used., the quantity of said media being dependant on its Specific Surface Area (SSA) and primarily on the fish load (biomass) in the Water Feature. (Additional information on SSA and fish load can be found on the internet with a simple web search.)

This brings us to the real purpose of this article; the fact that, in most instances, manufacturers of bio-filtration units supply incomplete and often misleading information on actual filter performance. Some only give the maximum flow rate, many rate their filter on total gallons of pond capacity (Is that without fish? If it is with fish, how many?), still others classify their filters pond capacity with sub classifications of ‘No fish, a few fish, or a heavy fish load”

How many are a “few” and what constitutes “a heavy fish load”. Some give the maximum number of fish in total inches of length which can be dangerously misleading (a 10” fish has considerably more biomass and produces proportionately more waste than two 5” fish of the same specie). One manufacturer does correctly state that it depends on the type of filter media used. Only one manufacturer, that also supplies the media with their filters, gives an actual maximum fish load (in pounds). A koi length/weight calculator is available at http://www.cnykoi.com/calculators/calcnh3c.asp.

Is it surprising then that because of this negligence on the part of the manufacturers new pond owners quickly begin to have problems maintaining water quality? Could this all be due to the fact that they were given incomplete information on the performance abilities of the biological filter they purchased?

Is it truly negligence on the part of the manufacturers? Or carelessness? Or incorrect prioritizing of published technical information? Or is this crucial information withheld knowing that subsequent problems may arise forcing the consumer to purchase yet another piece of equipment or an otherwise avoidable chemical treatment?

It is time that the Water Feature equipment and supply manufacturers adopt industry wide standards concerning labeling and product performance information that would be truly beneficial to the consumer. Knowingly withholding any vital product information seems, at the least, unethical and unprofessional. Some may even feel, and understandably so, that it borders on the criminal.

Before you purchase any filtration unit, ask the important questions and insist on detailed and specific answers. The health and longevity of your fish depend on it. When you care enough….!

...and a cast of thousands!

2011-06-16T15:04:00.000-05:00

An excerpt from a movie poster? Could be, but no. I am talking about the multitude of micro-organisms (plant and animal) that call your pond home. I briefly discussed those that live on the bottom or Benthic layer in a previous post. In this post I want to explore those that live in the water column. They are commonly referred to as Plankton.

Plankton is divided into two (2) groups-

-Phytoplankton which is microscopic plants (algae) and some species of bacteria. These are the primary producers in the aquatic food chain.

-Zooplankton consists predominately of crustaceans and rotifers. They are usually larger than phytoplankton. They are predators and feed on phytoplankton and other zooplankton.

As an example of the sheer magnitude of their numbers, in a fish culture pond it is not unusual for plankton (dry weight) to account for up to 50% of the total biomass (dry weight) of the pond (this includes the fish). That is a lot of little critters! But very important little critters! They comprise the bulk of any aquatic food chain and web. A pond’s biological balance would collapse without their existence in such great numbers

Your Koi and/or Goldfish may be the Stars in your perception but, in biological terms, they are only bit players. They, because they are the top consumer in the food chain, are dispensable as far as maintaining biological balance. The lower an organism exists in the food chain, the more indispensable they become. This truly makes the existence of algae, for instance, more important than the fish. This is not to say that you can’t have too much algae. An overgrowth of algae can be problematic for the balance in a pond as can too many fish.

The USDA recently did away with the Food Pyramid in favor of a dinner plate diagram as a nutritional guide. I prefer the pyramid for it emphasizes the real importance of the food groups. Those most important and also in greatest numbers are at the bottom or base of the pyramid. The same applies to the food chain in a pond. Those organisms of greatest number and importance are at the bottom. Phyto-plankton.are part of this pyramid base.. Zooplankton are just one level higher in the pyramid.

All plankton serve as nutritional sources for organisms higher in the food chain. Insects, amphibians, annelids and some fish specie look to plankton as a food source.

Just observe all of the activity around your pond. It can be quite a pageant. A pageant that requires........... ‘a cast of thousands’.

Algae - The Propitious PITA

2011-04-08T12:56:00.000-05:00

Listen in on most any conversation about ponds and you will eventually hear the word Algae mentioned, many times along with some unpleasant descriptive adjectives. In the majority of cases, it is the ‘Green Algae’ that is the subject of the verbal derision.

It is true that out-of-control algae can turn an otherwise beautiful Water Feature into a most disgusting eyesore. It is wrong, however, to put any blame on this simple organism. “Don’t shoot the messenger”. Algae are not the problem. It has been explained in countless means of communication, for countless times and for countless years that….excess algae is a direct result of an excess nutrient level in the pond water. So, if your pond has an abundance of algae, it is your fault because: (a)You have too many fish; (b) You overfeed your fish; (c) You do not have a sufficient size aquatic plant population; (d) You allow leaves, twigs and other organic debris to accumulate in you pond; (e) All of the above.

Algae are, by their nature, quite beneficial. Nearly all algae are photosynthetic (the ability to produce Oxygen), so much so that the total amount of Oxygen produced by all algae EXCEEDS the total amount produced by the entire plant kingdom. That’s impressive!

Algae are an extremely important source of nutrition for most aquatic organisms and are an integral part of the foundation of the overall food web. Extremely high in nutritional value, several species of Algae are used for human consumption, from wrapping sushi (Nori-Red Algae) to nutritional supplements such as Chlorella and Spirulina (Green Algae).

There are over 300,000 identified species of algae (no one knows the exact number) and around 6,000-7,000 species of green algae (again no one know for sure) and range in size from the single cell microscopic to the multi-cell giant sea kelp

Algae have existed in vast numbers for millions of years. The sparkling white sand beaches of the Caribbean and many other areas in the world are largely the sun-bleached and eroded calcium-carbonate remains of green algae.

They are an important part of the Nitrogen cycle (the use of Nitrates as an energy source) and the Carbon cycle. Like Oxygen, the total amount of Carbon contained in all algae exceeds the total amount contained in the entire plant kingdom.

In conclusion, the next time you think of hurling epithets at the green invasion of your pond, just remember all of the beneficial aspects of algae and, more to the point, remember that it is likely your fault. Like any other pesky organism…quit feeding it and it will go away.

Archaea: The not-so-new kids on the block

2011-03-28T11:48:00.000-05:00

The oxidation of Ammonia was for decades believed to be performed solely by certain autotrophic bacteria (i.e. Nitrosomona) Later it was discovered that this oxidation process was also performed by certain Heterotrophic bacteria under certain conditions that were completely void of any organic carbon source or oxygen.

With the advent of gene sequencing, it was discovered in 1977 that what was thought to be a type of bacteria was actually not a bacteria at all, but an entirely different and new domain. This group of microorganisms was given the name “Archaea”.

Originally thought to be exclusively extremeophiles that lived in environments such as hot springs and very acid and saline conditions, it was recently (2006) discovered and subsequently verified (2008) that Archaea are ubiquitous and exist in all environments and more importantly play a very large role in the oxidation of Ammonia. Unlike nitrifying bacteria, nitrifying Archaea are suspected to be adaptable to a wider range of temperatures. Evidence of their existence has been found in the very cold waters of Antarctica.

Unfortunately, at the present time, Archaea are very difficult, if not impossible, to reproduce under laboratory conditions, so current knowledge is limited.

No nitrite oxidizing Archaea have been detected to date, but, given the relative infancy and current limits of research, this does not mean that they don’t exist.

The results of future research could have a major impact on how we view the basic biological processes of our ponds. For example, it has already been shown that Archaea tend to colonize the rhizosphere (root zone) of aquatic plants. This fact alone increases the importance of aquatic plantings in maintaining water quality. Archaea’s wider tolerance of extreme temperatures could possibly shed light on why some Northern ponds endure winter stresses better than others.

Much still needs to be learned about this newly named, but very old, microorganism.

The Benthos

2011-03-11T15:57:00.000-06:00

"The length of food chains is a crucial determinate of the functioning of ecosystems," says Alan Tessier, program director in the National Science Foundation (NSF)'s Division of Environmental Biology.

Roughly translated, diversity in an eco-system is of prime importance. This diversity is not limited to the number of levels in a food chain, but the diversity within each level provides a key element of stability to the entire food chain. The lower the level of the food chain, the more important and crucial this diversity becomes.

Biofilm, as indicated in the previous post, forms the true foundation upon which an aquatic food chain is established. Also of extreme importance is what is called the Benthic layer or Benthic zone.

The Benthic zone is the ecological region at the lowest level of a body of water including the sediment surface and some sub-surface layers. This region extends from water’s edge to water’s edge and encompasses the shallow (littoral) regions as well as the deepest (i.e. the profundal region that exists is lakes).Organisms living in this zone are called Benthos. They generally live in close relationship with the substrate bottom; many such organisms are permanently attached to the bottom. The superficial layer of the soil lining the given body of water, the benthic boundary layer or BBL, is an integral part of the benthic zone, as it influences greatly the biological activity which takes place there.

Benthos, in fresh water biology, refers to organisms at the bottom of bodies of water, such as lakes, ponds, rivers, and streams. The population make up of these communities is influenced not only by type of body of water, but also by the depth of the water plus nutrient availability and, of course, pH and temperature.

There are two types of Benthic organisms:

Epifauna- live on the surface of the bottom

Infauna- burrow into the sediment on the bottom

Of the two, Epifauna is the most prevalent form found in an eco-system pond, although some Infauna may exist depending on depth of bottom gravel and the amount of sedimentation.

They are also classified as to size:

Microbenthos (<100mm) includes bacteria & protests

Meiobenthos (100-500mm) includes small metazoan (multicellular animals) and larger protists (single cell organisms).

Macrobenthos (>500mm) includes larger metazoa and Megabenthos

Megabenthos (very large.) crustaceans, mollusks, etc.

By what they eat:

Herbivores- feeds on plant material

Carnivores/predators- feeds on other benthic organisms

Detritivores- feeds on dead plant and animal material

And how they eat:

Suspension feeders- eats using a mucus-covered appendage that catches particles in water column

Filter feeders- strain particles from the water column

Deposit feeders- ingest sediment and removing the nutrients

In our next post, we will delve deeper into the roles that each individual type plays in the complex world of an aquatic eco-system. It will be the beginning of an interesting journey into a world of such immense activity that, by comparison, the activity level of your fish is like watching paint dry.

Biofilm

2011-01-30T16:26:00.000-06:00

Biofilm-

"A complex structure adhering to surfaces that are regularly in contact with water, consisting of colonies of bacteria and usually other microorganisms such as yeasts, fungi, and protozoa that secrete a mucilaginous protective coating in which they are encased. Biofilms can form on solid or liquid surfaces as well as on soft tissue in living organisms, and are typically resistant to conventional methods of disinfection. Dental plaque, the slimy coating that fouls pipes and tanks, and algal mats on bodies of water are examples of biofilms. While biofilms are generally pathogenic in the body, causing such diseases as cystic fibrosis and otitis media, they can be used beneficially in treating sewage, industrial waste, and contaminated soil." (The American Heritage® Science Dictionary)

Biofilms are a crucial part of an aquatic eco-system. The microorganisms that make up biofilms form the basis for food webs that nourish larger organisms such as insect larvae, which are consumed by fish. Even plants benefit from naturally occurring biofilms.

The instant that the first water contacts any surface of your pond, whether it be liner, rock, filter media, plants etc., biofilm begins to form. Initially the first surface deposit is dissolved organics which neutralize the electrical charge of the surface which would otherwise repel bacteria and other microorganisms. This initial layer of organics also serves as a nutrient source. Bacteria then begin to colonize the surface by secreting strands of sticky polymers which holds the biofilm together and secures it to the surface. These polymers also serve to trap nutrients and act as very strong protective barrier against toxins.

As nutrients accumulate, the original bacteria multiply. These offspring bacteria produce their own sticky polymer. Soon a colony of bacteria is established. These “other bacteria and fungi become associated with the surface following colonization by the pioneering species over a matter of days.” Borenstein (1994),

Biofilm is made up of microorganisms and a polymeric web Interestingly, in a well established biofilm, most of the volume is the sticky polymer matrix (75%-95%). This matrix holds quite a bit of water and makes the biofilm covered surface slippery. This is why, especially in bare liner ponds, is it difficult to maintain traction while you are walking in your pond.

A fully developed biofilm is a complex mutually beneficial community of various microorganisms living in a customized microniche.

“Different species live cheek-by-jowl in slime cities, helping each otherto exploit food supplies and to resist antibiotics through neighborly interactions. Toxic waste produced by one species might be hungrily devoured by its neighbor. And by pooling their biochemical resources to build a communal slime city, several species of bacteria, each armed with different enzymes, can break down food supplies that no single species could digest alone. The biofilms are permeated at all levels by a network of channels through which water, bacterial

garbage, nutrients, enzymes, metabolites and oxygen travel to and fro. Gradients of chemicals and ions between microzones provide the

power to shunt the substances around the biofilm.” Slime City (Coghlan 1996)

A mature biofilm may take several hours to several weeks to develop. A fully developed biofilm is able to move water through the entire matrix, supplying nutrients and transporting wastes. Biofilms may be very thin to several inches thick. The biofilms that are usually encountered in an aquatic eco-system are measured in microinches. A microinch is equal to one-millionth of an inch.

Biofilm covers every submerged and constantly wet surface associated with a pond. It is on the rock, liner, plants, skimmer, biofilter and media, even inside of the pump and related piping. The biofilm in one location will be different in make up than that in another location. Factors such as light, water movement, temperature and availability of nutrients will determine the member microorganisms of each community. The very same parameters that we test for to ensure healthy fish also influence the membership of the biofilm community.

It is within this biofilm that nitrification and denitrification take place along with other chemical and organic conversion processes. It is the base upon which all aquatic life depends.

Are Koi Wusses? Part IX - Denitrification

2011-01-24T14:53:00.000-06:00

Denitrification is the bacterial process where Nitrate is reduced to gaseous Nitrogen. This is accomplished in a series or steps: Nitrate to Nitrite, Nitric oxide, Nitrous oxide and finally Nitrogen gas.

Denitrification is accomplished by primarily Heterotrophic and Autotrophic bacteria, with Heterotrophic bacteria playing the larger role. Autotrophic bacteria utilize sunlight and inorganic chemicals as an energy source, whereas Heterotrophic bacteria rely mainly on organic carbon as an energy source.

Denitrification takes place under special conditions in both terrestrial and aquatic ecosystems. It occurs where Oxygen is depleted, and bacteria utilize nitrate in the respiration process. Due to the high concentration of oxygen in our atmosphere, denitrification only takes place in environments where oxygen consumption exceeds the rate of oxygen supply, such as in some soils and groundwater, wetlands and the substrates in the bottom of a pond.

In a properly constructed eco-system pond, denitrification is a normally occurring process. A classic Koi pond, however, because of its method of construction (no rock or gravel; bare liner), does not have any areas of low or depleted Oxygen to promote the growth of these denitrifying bacteria. External methods must be used for denitrification such as trickle towers, fluidized beds and rotating biological contactors. Additionally, attention should also be given to ORP (oxidation reduction potential) levels.

In the previous post, the toxic level of Nitrate was shown to be arbitrary at best. This was focused on high end Nitrate levels. The complete absence of Nitrate (in an eco-system pond), however, is definitely cause for concern. In the absence of Nitrate, the denitrifying bacteria will utilize Sulfur as a replacement, producing Hydrogen sulfide (rotten egg gas) which is highly poisonous. It should be pointed out that, for this scenario to occur, the pond would have to be completely neglected……a total lack of maintenance or ownership responsibility or concern.

This, then, is where the Nitrogen cycle comes full circle. With very few exceptions, all living organisms rely on this continuous process for their existence.

The subject may be debated for years to come, but it has been shown that Carp (Koi) are some of the most durable and adaptable fish in existence. I think that the Australians have summed up the hardiness in Carp (Koi) by referring to them (not very affectionately) as “River Rabbits”.

We can now begin venturing into the world of aquatic life; exploring the succeeding higher levels of the Food Web and how they interact.

Are Koi Wusses? Part VIII - Nitrate

2011-01-17T09:56:00.000-06:00

Nitrate is the product of the oxidation of Nitrite by, primarily, the bacteria genus Nitrobacter, and, to a lesser extent, the genus Nitrospira.

It is generally believed that Nitrate is toxic to Carp (Koi) only at very high levels. There is much disagreement as to at what level does Nitrate begin to have toxic effects. This is primarily due to the lack of research done on this subject as relates to Carp (Koi). Some believe that most fish easily tolerate levels below 100 mg/L; others claim that levels above 120 mg/L are toxic; still others state that fish can tolerate levels up to 500 mg/L.

The important aspect of Nitrate toxicity to remember is that it is species specific. Scientific research has shown that Nitrate levels of 10 mg/L, which is the maximum safe level for drinking water, IS toxic, at least in the long term, to certain sensitive freshwater invertebrates, fish and amphibians.

The toxicity level in an eco-system pond is, for all practical purposes, a non-issue.

Aquatic plants utilize Nitrate as a food source. If excessive Nitrate occurs, Nature has a built in balancer…ALGAE. We know that an abundance of algae (Pea Soup) is symptomatic of more basic problems such as overfeeding, overcrowding and accumulation of organic debris, among other things and corrective steps should be taken. On the flip side of the coin, some level of Nitrate SHOULD be detectable. A complete absence of Nitrate indicates water quality issues and could be more problematic than an excessive amount.

(NOTE: Algaecides are not recommended as their use will very likely result in reduced Oxygen levels while doing nothing to reduce the nutrient level in the water. In fact, as the algae die and decompose, nutrients are released back into the water bringing the process full circle.)

I find it hard to imagine that Carp (Koi), given their native habitat, their preference for muddy, nutrient rich water and their adaptability, would ever have a problem with Nitrate toxicity…. at least in a Garden Pond (eco-system) setting as long as Nitrate levels increased over time and the increase was not large and abrupt.

The true Koi Pond, because of its lack of plants, does present problems with Nitrate levels. Not because it is a health problem (albeit remote) for the fish, but because of the potential need for algae control. A true Koi Pond is constructed specifically for the viewing of its occupants, so water clarity is of prime concern. Excessive Nitrate levels in Koi Ponds are usually controlled by water changes and by the process of Denitrifcation.

This will be the subject of our next post.

Are Koi Wusses? Part VII - Nitrite

2011-01-11T13:29:00.001-06:00

We know that the product of Ammonia oxidation is Nitrite. This is also toxic to Carp (Koi) at very low levels. Any reading greater than 0.06 mg/L is considered lethal. This level is roughly equivalent to one drop in a pint of water.

Like Ammonia, Nitrite toxicity is influenced by both pH and temperature .In one study, two (2) different groups of Carp (Cyprinus carpio) were subjected to nitrite levels of 0.0667 for 48 hours at temperatures of 14C/57F and 20C/68F. The mortality rate for each group was 30% and 51% respectively.

In addition toxic effects of nitrate are more likely at low dissolved Oxygen levels.

Nitrite toxicity occurs as Nitrite enters the fish by way of the gills and passes into the circulatory system (Perrone, 1977). Toxic effects of nitrite include oxidation of hemoglobin to methemoglobin, a form incapable of binding molecular oxygen (Brown and McLey, 1975).

Fish with methemoglobin can be detected by the colour of the blood and also by brown colour of the gills (Brown Blood Disease). As nitrite rises, the fraction of methemoglobin in the blood reduces the oxygen carrying capacity of the blood (Cameron, 1971). Fish with elevated levels of methemoglobin may suffer from anoxia (Tomasso, 1981). . Since methemoglobin does not transport oxygen, asphyxiation is the principal reason fish die from nitrite poisoning

Nitrite is less toxic than Ammonia, but the toxic effects of Nitrite occur much more rapidly than those of Ammonia.

Chloride is used to “treat’ Nitrite toxicity. This may be Sodium Chloride (Pond Salt) or Calcium Chloride, which is more expensive. The chloride portion of salt competes with nitrite for absorption through the gills .If problems with Nitrite levels exist, maintaining at least a 10 to 1 ratio of chloride to nitrite in a pond effectively prevents nitrite from entering Koi. As a general rule, 50 to 100 ppm chloride in pond waters will guard against high spikes of nitrite concentration. 1,000 ppm of salt is equal to a 0.1% level. (Note: This should be done only if a Nitrite problem is detected. Maintaining salt levels will over time result in parasites and other pathogenic organisms adapting to these salinity levels making them harder to control through the normal “Salt Treatments” .Use Salt only as a temporary fix. Adequate bio-filtration (bioconversion) will maintain safe nitrite levels.)

It should be noted that Carp(Koi) can survive ‘Brown Blood Disease’ if treated in time, but with a resulting lowered immune system making them more susceptible to other infections that can occur for up to 3 weeks after the “Brown Blood Disease’ is cured.

Carp(Koi), though highly adaptable are as susceptible to Nitrite poisoning and it’s effects as any other fish
Nitrite level is probably the most important water quality parameter because it’s effects occur rapidly and should be tested for frequently along with Ammonia.

Next Post: Nitrates

Are Koi Wusses? Part VI - Ammonia

2011-01-05T12:11:00.007-06:00

Ammonia is one of several different forms of Nitrogen. The transition from one form of Nitrogen to another is commonly referred to as the Nitrogen Cycle.

Nitrogen is a requirement for life in all organisms because it is an essential part of RNA, DNA, and protein.

Nitrogen comprises over 75% of the atmosphere, but this huge reservoir is not usable by most organisms. It must be converted by lightning and nitrogen fixing bacteria.

This is the first of the five processes in the Nitrogen cycle--- fixation, uptake, mineralization, nitrification, and denitrification – and are all driven by microorganisms. For the purposes of this discussion, only the last two processes are of interest.

Nitrification is defined as- “The process by which bacteria in soil and water oxidize ammonia and ammonium ions and form nitrites and nitrates”.(The American Heritage® Science Dictionary).

The oxidation of ammonia into nitrites is accomplished by two genuses of bacteria, Nitrosomonas, primarily, and Nitrosococcus, to a lesser extent. Generally, their optimum temperature for growth is 30C/86F and the optimum pH is 7.5 – 8.0.

They have a relatively slow reproductive rate. Nitrifying bacteria reproduce by binary division. Under optimal conditions, Nitrosomonas may double every 7 hours. In the time that it takes a single Nitrosomonas cell to double in population, a single E. Coli bacterium would have produced a population exceeding 35 trillion cells.

Ammonia-oxidizing bacteria are also known to be unusually resistant to starvation conditions. Nitrosomonas europaea can immediately respond to the addition of ammonia after nearly one year of starvation.

It is commonly known that ammonia is toxic to, not only fish, but also other aquatic organisms. In water, ammonia exists in two forms – ionized (ammonium) and un-ionized (free ammonia). Ionized ammonia is, for the most part, harmless. It is the un-ionized form that is toxic and this toxicity is directly influenced by both pH and temperature with pH effecting the greater change. As pH (and temperature) rises, the toxicity of un-ionized ammonia rapidly increases.

Although 0.00 test results for total ammonia are possible and usually desired in a true Koi pond, it is both unrealistic and unnatural to strive for a complete absence of ammonia in an eco-system pond, but levels should never be allowed to reach toxicity. The following shows how Carp (Koi) may react to different levels of un-ionized ammonia (in mg/L).

0.00 is ideal. Values up up 0.019 might be tolerated for extended periods.

0.020 - 0.049 may be tolerated, but will cause long term harm

0.050 - .0.199 may be tolerated for a few days, harmful

0.200 - 0.499 May be tolerated for a day or two, very harmful

>0.500 Extremely Toxic, Fish should be moved to alternate location

(Koi and Water Garden Society of Central New York)

Next: Nitrites

Are Koi wusses? Part V - pH

2010-12-29T11:25:00.000-06:00

The pH of water is important, not only to Fish, but to all aquatic life because pH affects the ability of fish and other aquatic organisms to regulate basic life-sustaining processes, primarily the exchanges of respiratory gasses and salts with the water in which they live. Inability to adequately regulate these processes can result in numerous non-lethal effects and even mortality, in cases when pH exceeds the normal range physiologically tolerated by aquatic organisms.

Unfortunately, there is no definitive pH range that is safe for all aquatic organisms. The acceptable pH range for aquatic life, especially fish, is dependent on other factors, including, but not limited to, prior pH acclimatization, water temperature, and dissolved Oxygen levels.

Our focus is the adaptability of Carp (Koi). Let’s look at some limits that have been determined by various studies.

-The lower pH limit for Carp (Koi) is between 5.0 and 5.5. Below this mortality occurs.

-The growth rate of Carp (Koi) is reduced at pH levels of 5.5 to 6.0.

-At pH levels of 8.0 to 8.5, the motility of Carp (Koi) sperm is reduced, thusly affecting the spawning process.

-Carp (Koi0 avoid pH levels of 9.0 to 9.5 (Goldfish avoid levels of 8.5 to 9.0).

-Carp (Koi) cannot survive at pH levels over 11.0.

-Carp (Koi) lose the ability to absorb Oxygen as pH decreases, with this becoming increasingly more severe at pH levels below 6.5.

We can see, as a result, that Carp (Koi) can survive in a pH range of 5.5 to 11.0. This may be the survival range, but is definitely not what we have termed a ‘Comfort Zone”.

The consensus of all examined sources would indicate that this pH ‘Comfort Zone’ is 6.5 to 8.5. This is further substantiated by the results of a test that showed that Carp (Koi) could be moved between different pH levels without any chronic effects as long as both pH levels fell within this range of 6.5 to 8.5. Any effects that were caused were temporary and non-lethal with the fish adapting and returning to normal within a short time. However, if the fish were transferred to a pH outside of this range from any level within this range, chronic effects or mortality usually occurred. In other words, Carp (Koi) will adapt to a sudden pH change of 6.5 to 8.0, but will suffer permanent physiological damage and even death if suddenly transferred from 8.5 to 9.0. They can adapt to changes outside of the ‘Comfort Zone’ when these changes are gradual This is evident in the fact that they are subject to diurnal fluctuations in pH in their natural environs, with the lowest being at dawn and the highest being in late afternoon, either or both of these levels being outside of their pH ‘Comfort Zone’.

Not only is this pH range of 6.5 – 8.5 ideal for Carp (Koi), except during spawning where a range of 6.5 - 8.0 is more suitable. It has also been proven that the range of 6.5 - 8.5 will promote the most diverse, healthy and productive aquatic life.

In our next post, we will begin discussing the Nitrogen cycle starting with Ammonia.

Are Koi Wusses? Part IV-Oxygen

2010-12-21T12:00:00.004-06:00

Oxygen comprises 21% of the Earth’s atmosphere by volume and is vital to the existence of all higher animals. Some animals have developed, over time, an amazing efficiency in the utilization of Oxygen. Fish make up a large part of this group, with some being even more efficient than others. Members of the Carp family are some of these fish.

Fish respiration is very efficient. They possess the ability to remove up to 80% of Oxygen in water. Compare this to an efficiency rate of 27% for humans and it is quite impressive, but it is also necessary given the fact that, in fresh water, the normal level of oxygen, by volume, is 6-8 mg/L which is a tiny fraction of 1%.

Added to this amazing ability is the fact that members of the Carp family have the means to survive, for a period of time, at very low (hypoxic) oxygen levels. Goldfish (Carassius auratus auratus) can actually survive for extended periods with NO Oxygen (Apoxia).

Oxygen in the aquatic environment is usually measured in mg/L and in percent of saturation. Saturation is the normal maximum level of Oxygen that water can hold at a given temperature and atmospheric pressure. Water with no oxygen is termed anoxic, 1% to 30% saturation is termed hypoxic, 31% to 100% is termed normoxic and any level over 100% is termed hyperoxic.

A “healthy” aquatic system should rarely experience less than 80% saturation. This means, for example, that a Pond that is located at sea level with a water temperature of 20C/68F should have an oxygen level of at least 7.3 mg/L. This same Pond at 26C/79F should have a minimum level of 6.6 mg/L. This lower level is because water loses its ability to retain Oxygen as temperatures increase, so saturation levels decrease.

One study states that Carp (Koi) can survive for 5hrs at 15C/59F under anoxic conditions. This adaptability is in inverse relation to temperature. As temperature rises, the time period of toleration decreases.

What about hyperoxia or super-saturation? Experiments have shown that “hyperoxia did not cause any visible changes in fish behavior, but at the biochemical level a serious stress was indicated. In fact, tissue-specific changes……did not return to normal even after 36 hrs of normoxic recovery”(Lushchak et. al. 2005).

So what does all of this mean?

As stated previously, Carp (Koi) are extremely adaptive. They can tolerate extremes in Oxygen levels for limited periods of time with no adverse effects given sufficient recovery time. Oxygen levels between 31% and 100% saturation are acceptable. The lower limits of this range are, however, not recommended. This is due to the fact that in any 24 hour period Pond Oxygen levels will fluctuate as temperatures change. A 40% saturation at noon will most probably mean an anoxic condition existed pre-dawn. 70% saturation is suitable for Carp (Koi), but 80% saturation is best for the entire eco-system.

How important is pH? Next!

Are Koi Wusses? Part III-Temperature

2010-12-11T11:18:00.003-06:00

“It’s hot enough to fry an egg!” “It’s colder than a well-digger’s….”

Descriptive phrases meant to indicate that the prevailing temperatures are outside of our human ‘comfort zone’. Do Carp (Koi) have comfort zones as relates to temperatures? In a manner of speaking, the answer is… Yes! Temperature has a direct effect on the physiological processes of Carp (Koi).

Every living organism has a temperature range in which they easily maintain what is termed homeostasis. Homeostasis is defined as: the tendency of a system, esp. the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus tending to disturb its normal condition or function. (Dictionary.com)

Outside of this range, discomfort (stress) occurs as an organism attempts to adapt. If the variance is far enough outside the ‘comfort zone’, the organism is unable to adapt, stress becomes too great and mortality occurs.

When we are cold, we shiver. When we are hot, we perspire. We exhibit noticeable signs. A Carp (Koi), however, does not shiver or sweat. So how are we able to determine the ‘comfort zone’ of Carp (Koi), as relates to temperature?

Respiration!!

The results of a study by the Agricultural Institute, University of Louvain (Belgium) published in 1957 show that Carp (Koi) exhibit a fairly stable respiratory rate between 20C/68F and 34C/93F. Above this range, the respiration rate rapidly increases until death occurs at 36C/97F for large fish and 38C/100F for small fish. Below this range, the respiration rate decreases and becomes extremely slow, One (1) every 60 seconds at 4C/39F. This study did not encompass temperatures below 4C/39F.

Even though no discomfort (stress) is manifested between 20C/68F and 34C/93F, ideally we want the temperature to be close to the midpoint of this range which is 27.5C/81-82F. This is well above the median temperature recommended by many sources, but is shown to be the ideal temperature for the Carp’s (Koi’s) optimum metabolism.

Temperature is as influential on the health and well-being of Carp (Koi) as are the other factors mentioned in the previous post.

Carp are extremely adaptable fish, but even this adaptability has it’s limits, the main one being time. Any acclimation to a new environment, or even one environmental factor or parameter, must be gradual. This includes temperature. The adaption period in abrupt temperature changes may run from 48 hours to as much as 14 days in extreme cases and even mortality if the temperature differential is too great. During this period the fish will be stressed One way that this stress will manifest is Ammonia autointoxication, which we will cover in a later post. The old admonition, when adding new fish to a Pond, to always float the bag containing the fish for 15-20 minutes does not really accomplish anything. The fish will continue to adapt to the temperature change for probably several days.

Next: Oxygen

Are Koi wusses? Pt. II-General Parameters

2010-12-01T11:42:00.004-06:00

Koi (Cyprinus carpio) are probably one of the world's most adaptable specie of fish. Originating in the Caspian, Black and Aral Seas where they mostly inhabited the river deltas, such as the Danube, they developed the physiology to thrive in eutrophic (characterized by an abundant accumulation of nutrients that support a dense growth of algae and other organisms, the decay of which depletes the shallow waters of oxygen in summer) waters. These are waters that are heavy in phosphates and nitrates which promote abundant plant growth and which also support a very diverse and complex Food Web. These conditions are, in part, duplicated in the mud ponds used by Koi breeders.

These conditions, however, are not desirable in a Water Feature that is part of one's personal landscape.The fantastic, and sometimes dazzling, coloration of Koi can only be fully appreciated in waters that are clear. Water clarity, or lack of, does not appear to have any physiological effect on Carp There are, however, other chemical water quality parameters that DO

Any Pondkeeper knows, or certainly should know, that chemical factors such as pH, Ammonia, Nitrite, Nitrate, Dissolved Oxygen along with Alkalinity, Hardness, Phosphate, Salinity and Temperature can affect the health and longevity of every aquatic organism, including fish. But what are the desired quantitative levels of these various factors? Well......It seems that there is a wide range of recommendations as evident in the chart below. This chart shows suggested levels from retailers, breeders, organizations and governmental agencies.

Parameter	Source a	Source B	Source C	Source D	Source E
pH	6.5 – 9.0	7.2 – 7.8	7.5 – 8.5	6.0 – 8.0	7.0 – 8.0
Ammonia	<.1 ppm	N/A	0	0 - .08 mg/l	0 - .01 mg/l unionized
Nitrite	< .2 ppm	0.0-.3 ppm	0 – .4 ppm	0 - .06 mg/l	0 - .01 mg/l
Nitrate	< 50 ppm	< 80 ppm	0 – 200 ppm	N/A	9 – 20 mg/l
Dissolved Oxygen	> 5.0 mg/l	N/A	9 mg/l @ 50F	4 – 10 mg/l	8 – 12 mg/l
Temperature	N/A	N/A	79F – 81F	65F – 75F	65F – 77F
Alkalinity	50 -170 ppm	N/A	120 – 180 ppm	50 – 350 mg/l	100 – 250 mg/l

As can be seen, the range of recommendations is quite varied and large

This chart, at first glance, is confusing. Who's recommendation is correct?

Well, in actuality, as relates to Carp, they all are! This attests to the adaptability of Carp.

In successive posts, we will take a closer look at each of these chemical factors. Next up: Temperature.

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Are Koi Wusses? Part 1-Introduction

2010-11-27T13:04:00.006-06:00

The other day, lacking the motivation to do anything else, I was thumbing through some of the many catalogs that I receive from various Water Feature supply distributors. Although I have done this many times in the past, this particular time, for some reason, I was struck by the vast array of chemical treatments on the market for both altering water chemistry to maintain quality, and medicinal products for treating every conceivable curable fish health problem with the exception of, maybe, a runny nose. (Do fish have runny noses?...... How would you know?)

The primary target fish specie for the vast majority of these products is Koi, (Cyprinus carpio, Nishikigoi, Carp).

Are these aquatic creatures that some literally fawn over, these Living Jewels, really that fragile and susceptible to parasitism and infectious disease as we would, subconsciously, be led to believe? I think not!

Koi are a decorative variety of the Common Carp. It is not a separate species. This is evident in the fact that, when Koi are allowed to spawn without any external selection (culling), they will, over time, invariably revert to the black coloration of the Common Carp. A true separate species would be genetically stable.

It therefore follows that we only need to look at the physiology of the common Carp when left to it’s own natural devices in determining the natural sturdiness of the specie.

Carp are usually found in still or slowly flowing waters, lakes and permanent wetlands, commonly with silt bottoms (Environment ACT Undated).They have a greater tolerance of low oxygen levels, pollutants and turbidity than most native fish, and are often associated with degraded habitats, including stagnant waters (NSW Department of Primary Industries 2005). They are most abundant in streams enriched with sewage or substantial runoff from agricultural land and are rarer in clear, cold waters and streams of high gradient. In fact, they are cultured in rural southern Asia in rice fields, which are reported to be the richest habitats of aquatic organisms (Saikia & Das 2009).

Doesn’t sound like a fish that requires pampering, does it? No Wuss fish here!

So exactly what are the water chemistry tolerances that Koi can adapt to? This will be explored in the next post.

Welcome

2010-10-16T13:03:00.002-05:00

I am launching this Blog as a means to provide to all Pond Keepers....... large or small, Koi or Goldfish, Formal or Water Garden.......the latest in developments in the Water Feature industry and community. From new products to new laws to the latest in scientific research, we will attempt to keep our followers up to date. I will, of course, relate how I may think you may be affected as a Pondkeeper. I will also cover many of the basics with the emphasis on WHY.

If there is a subject or area of Pondkeeping that you would like explained or are just curious about, please post your question as a comment.