Aquaculture - Koi Diet

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While studying on anatomy of fish and the technical definition of "barbel" which is used for the fish sense of "smell" in location of food and whatnot, I came across this golden tidbit on another website.

The Fundamentals of Feeding Koi and Goldfish
By Stephen M. Meyer

Feeding Options
Carp and goldfish evolution has seen to it that the proper functioning of their digestive systems requires dietary variety over the long run. Monotonous diets are fine in aquaculture where fish are routinely culled out for market early in life, but ornamental pondkeeping aims for natural life spans, which places more subtle demands on fish-rearing techniques.

In this respect, no single food type, no matter how nutritious, represents an appropriate or healthy long-term diet for koi or goldfish. I doubt that any of the manufacturers of premium koi and goldfish food would claim that their products should be the exclusive diet of your fish. Therefore, you should make every effort to offer your koi and goldfish a varied diet (which does not mean different brands of pellets but rather different types of foods: vegetables, insects, etc.).

It is useful to think in terms of a base diet and a supplemental diet for your fish. The base diet provides the essential proteins, fats and most vitamins and minerals. The supplementary diet provides additional vitamins and minerals, but also other proteins and fats and, most importantly, variety.

After reading, I visted Wal-Mart and purchased some floating pellets and dehydrated "Baby Shrimp" specially formulated for Koi and Goldfish.

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Photographs of Snails, Catfish and Lily

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Here's a recent addition to the alternate site with my first microscopy shot of Qui nosce mysterium that's Latin for who the heck knows? and a lot of other "neat stuff" taken at the college.

John and Chad will have to help me identify all those neat critters that'll be seen floating up under the microscope...

WOW, Sharon. What a neat shot! The only thing I see in there is a chain of diatoms that I can't identify -- it could be /Melosira,/ /Skeletonema/, or /Biddulphia/.

I would love to see more plankton photos when you get them! I enjoyed the other photos also.

Terri K. Hathaway
Marine Education Specialist
North Carolina Sea Grant

A snapshot of Lily, the College's Bird-Dog

Video and Digital Photographs of Microscopic Worms

Videos and Photos of Microscopic Worms, February 22, 2007, Salt Water Sample from BCC

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Sodium Thiosulphate

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Water companies began adding Chloromites to tap water which is poison to fish. Sodium thiosulphate is used to get rid of Chloromites in tap water.

Sodium thiosulphate
Chloramine==Ammonia?

Use a standard sodium thiosulfate declorinator for both chlorine and chloramine. However, for chloramine use it double strength. Some (and I am being cagey here) products designated to neutralize chloramine are known by their manufacturers to be toxic to fish at concentrations higher than that recommended on the bottle. ie, you have to be fairly precise. The old standard however is very forgiving. No one advertises this as it is likely to hurt sales. Moderate plant growth will take care of any excess ammonia released by the application of sodium thiosulfate to chloramine.
Declorinators (like thiosulfate) will break the chlorine + ammonia bond and set the ammonia free (so as I am told). This replaces toxic choraimine with potentially toxic ammonia. Now, extra thiosulfate will handle the free clorine. So, that leaves the ammonia...

The concentration of the released ammonia will be related to the concentration of the original chloramine. The resultant ammonia concentration is something similar to the chloramine concentration. So, I think we are talking about 1 to 2 ppm (mg/l) of ammonia (to be diluted according to the % water change). For 50 % change you can have 1 ppm of ammonia. The amount of this that is toxic to fish will depend mostly on pH but also on temperature. (There is an equilibrium between toxic NH3 and non-toxic NH4). Worst case is high pH and high temperature. At 8.5 pH and 86 deg, 20 percent would be toxic NH3 (~ 0.2 ppm). This is a lot and roughly corresponds to lethal dose for 1-hr exposure.
• Ideally fish should be diagnosed by an authorised or qualified technician.
• Carefully calculate dose rates according to manufacturers label.
• Remember that some chemicals may not be approved for use with fish that are for human consumption.

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Biological vs Mechanical Filters

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Here's something interesting I learned this week in Aquaculture Practicum, from John (BCC Instructor).

A biological filter contains bacteria which convert ammonia to nitrite and nitrobactor converts nitrite into nitrate. Nitrate is plant fertilizer, which is much less toxic than nitrite.

Ammonia occurs naturally in the environment. A small amount of ammonia is generated when lightning strikes and reaches earth in rainfall. But most ammonia is produced by bacteria in water and soil as an end product of plant and animal waste decomposition. It is found in relatively low nontoxic concentrations in soil, air, and water and provides a source of nitrogen for plants.
In soils and water ammonia will go through many complex biochemical transformations. These transformations constitute what is commonly known as the nitrogen cycle.
Ammonia in Water
Water reacts with ammonia to form ammonium and hydroxide ions. Ammonia is often referred to as “unionized ammonia”. Ammonia is toxic to aquatic organisms but ammonium is non-toxic. There exists an equilibrium in water between the toxic ammonia and the non-toxic ammonium. The equation shifts back and forth depending upon existing or introduced environmental changes.
NH3 (aq) + H2O (l) NH3 · H2O (aq) NH4 + (aq) + OH - (aq)
(Ammonia in water) (ammonia+water) (ammonium + hydroxide ions)
The dynamic equilibrium between NH3 and NH4 + is affected by water temperature and pH (acidity). At a pH of six the ratio of ammonia to ammonium is 1 to 3000 but decreases to 1 to 30 when the pH rises to eight (becomes less acidic). Warm water will contain more toxic ammonia then cooler water. When sampling water for ammonia analysis both the temperature and the pH of the surface water body must be measured at the same time the water samples are collected. (See “Ammonia, pH and Temperature Calculator”)
If ammonia is directly spilled into surface water or if water used by a fire department to depress an ammonia vapor cloud is allowed to reach surface water, aquatic life can be harmed. Even at a concentration of 0.02 mg/L (48 hour LC50) unionized ammonia is lethal to some sensitive freshwater fish. That equates to about ½ a cup of unionized ammonia in one million gallons of water. Ammonia is also highly toxic to freshwater invertebrates having a 48-hour LC50 of 0.66 mg/L for Daphnia magna . Again, water contaminated with fertilizer ammonia should not be allowed to enter any storm drains, rivers, drainage ditches, wetlands or lakes.
From Ecological Effects of Ammonia

A mechanical filter stops all solids.


Biological Filters

John explains this is both a biological and mechanical filter

Biological Filter

Mechanical Filter
From What Is A "Biological Filter"?
By Stan and Debbie Hauter
Your Guide to Saltwater Aquariums.
The biological filter in a saltwater aquarium is nothing more than a place for bacteria to grow. Any surface in an aquarium which comes in contact with tank water and the nitrobacter & nitrosomona bacteria species that you created when you cycled the tank is part of your bilogical filter. The velocity of the water passing over the bacteria also affects the efficiency of the biological. The faster the water moves over the bacteria, the more efficient it is, up to the point where the bacteria is being stripped from the filter surface.
The efficiency (strength) of a biological filter is determined by its surface area and the amount of water passing over it. Some filter medium are more efficient than others. Aquarium glass surface area aside, here are the most popular biological filtration methods:

Canister Style Filters come in many different styles and sizes and can also be multifunctional.
Live Rock / Berlin Systems are the filters of choice for many SW aquarium purists.
Live Sand / Jaubert Systems are also very popular with many reef aquarists.
Undergravel Filters are among the first biological filters created for SW aquarium hobbyists.
Wet / Dry Trickle Filters were the next step after the UGF to dramatically improve efficiency.
Biological Filtration Polls show you which biological filters are popular with other habbyists.
Choosing Your Biological Filter Material shows you which materials are more efficient.
Knowing how each biological filter works and what it requires will make Choosing a Filtration System In 5 Easy Steps much easier.

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Constructing a CO2 Reactor

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Fig. 1 [(+/-)] CO2 reactors are used to deliver bubbles of carbon dioxide (carbonic acid) to plants growing inside an aquarium.


Fig. 2 [(+/-)] Plants thriving inside fully aquatic environment.

Fig. 3 [(+/-)] Pressure built up inside the CO₂ Reactor pushes the gas through the small plastic tube and into the tank for circulation. A small air stone is attached at the end of the tube (see figure 13). For information on airstones, go here, Air Stones for Aquariums.

"Air stones provide very fine air bubbles, much finer than those released from a piece of tubing attached to a pump. For the aquarium keeper this means more oxygen in the water. Oxygen absorption is improved by the large surface area of the smaller bubbles. Adequate oxygen can increase the amount of fish that your aquarium can hold." (e-aquarium.com.au)

A CO₂ Reactor of this nature should begin working within 1-2 days, and should last approximately two weeks. The process to construct a CO₂ Reactor involves a few simple steps and ingredients:

·Water
·Sugar
·Yeast
·Baking Soda

CO₂ for plants lowers the PH level in water, and improves water quality for fish.

Fig. 4 [(+/-)] Bottle which has been thoroughly cleansed of all liquids and fitted with plastic funnel.

Fig. 5 [(+/-)] Granulated sugar is added.

Fig. 6 [(+/-)] Measurements are approximate.

Fig. 7 [(+/-)] Yeast is an important ingredient in the creation of a CO2 Reactor.

"Yeasts are unicellular eukaryotic microorganisms classified in the kingdom Fungi. Approximately 1,500 species of yeasts have been described,[1] most of which reproduce by budding, although in a few cases by binary fission. Yeasts measure about 3µm varying across species. The yeast species Saccharomyces cerevisiae has been used in baking and fermenting alcoholic beverages for thousands of years. It is also extremely important as a model organism in modern cell biology research, and is the most thoroughly researched eukaryotic microorganism, which gathers information into the biology of the eukaryotic cell and ultimately human biology." (Wikipedia)

Fig. 8 [(+/-)] Yeast added to the mixture.

Fig. 9 [(+/-)] A clump of Sodium bicarbonate, Baking Soda is added.

Fig. 10 [(+/-)] Warm water is added until bottle is approximately 3/4 full.

Fig. 11 [(+/-)] All ingredients have been added and the bottle should be capped and firmly shaken.

Fig. 12 [(+/-)] Shaking the mixture helps sugar dissolve in the warm water. Yeast breaks down the sugar, converting it to carbon gas

...yeast causing fermentation can be detected by observation. The first indication of ferment is the appearance of tiny bubbles, which collect on the sides and the bottom of the vessel and then gradually rise to the top. These bubbles are a form of gas called carbon-dioxide, or carbonic-acid, gas. Gas, acid, and alcohol are three results of the action of the ferment. (Basics about Ferment)

Fig. 13 [(+/-)] A small hole should be drilled through the cap, to fit the line of plastic tubing. Care should be taken to ensure this hole is no larger than the tubing or gas will leak around the line instead of being pumped through into the aquarium. Securely tighten the cap on the bottle. The bottle will be under significant pressure as chemical reactions occur over the following two weeks.
An airstone is placed on the opposing end of tubing, inside the aquarium.

Related Links to Carbonic Acid in Water
CO₂ and Water Hardness
Carbonic Acid, Wikipedia
What happens when water mixes with carbon dioxide.
H2O + CO2 ->H2CO3 (carbonic acid). Hydrogen bonds to carbon instead of oxygen.
Making Carbonic Acid
Carbon Dioxide and Carbonic Acid, Chemistry Page
Chemistry and Aquaria
A series of solutions to common pH problems.
Airstones, how to clean and rejuvenate old airstones.

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