CO2 dosing and regenerating peat to culture Daphnia

[TyroneGenade]

Hi all,

Here is a little something I dug out of Scheel's tome ROTOW that I thought may be of interest... (This may need to be linked to the planted tanks section and Daphnia thread...) tt4n

Original text by JORGEN SCHEEL
taken from Keeping rivuline species in Rivulins of the Old World (1975), p. 18–19, TFH Publishing. [Text in square brackets not by original author.]

Most rivuline individuals take very much food and it is often not too easy to keep down the concentration of waste-products. Also, these fishes prefer food rich in proteins and their waste-products simply cannot be taken up by the plants because of the deficiency of carbon dioxide and an artificial supply of gas should be given. The usual system, with fermenting sugar-solution in a separate bottle for each tank, is not very practical for the killifish fancier. When much care is taken, another system might be used. Prepare a 5% [5 g to 100 mL] solution of sugar in water (about 6 ounces of sugar to each gallon of water)[˜96 g to 3.8 L] and add 16 cc. [mL] of this solution to each four gallons of aquarium water (1 cc. to each liter).

Best results are had when the sugar solution is stirred into the water and bad results are usually had when solid sugar is added directly to the aquarium. This method is very useful when the possible bad effects are understood and counteracted. First the sugar is converted into carbon dioxide and alcohol, which do no harm. Then the alcohol is converted into acetic acid and the oxygen needed for this process is taken from sulphates, resulting in a production of the poisonous hydrogen sulphide gas, which is very harmful for fishes. I have used this system in fifty tanks for more than two years without killing a single fish. The sugar solution usually is added to the tank every two weeks. It has been possible to maintain many tanks without renewal of the plants, peat and water for more than one year.

From section: Care of peat, page 20–21.

Aquarists who are used to sand or gravel as a bottom layer of their tanks, ussualy resist using peat because they consider this material to be very troublesome and so it is. When keeping so called “difficult” tropical fishes from the forest, the use of peat instead of sand renders certain major advantages, not only for reproduction but also in the keeping of feeble fishes.

Peat is an active material. It absorbs various chemical compounds and this is one of the reasons why peat is able to maintain a very clear water even in tanks with many fishes. Also, the peat gives a number of chemical compounds to the water which are useful during the reproduction of difficult fishes and to prevent attack from bacteria. Generally, it seems that the many advantages compensate for the disadvantages produced by the more difficult handling of the material.

First, the peat should be soaked in water and all the air in the material should be forced out by keeping the material in water for some weeks or by boiling it for some hours. You may add one handful of bicarbonate of soda to each three gallons of water used for the soaking or boiling of the fresh peat. The soda will extract brown compounds (and also some useful hormones) and the aquarium water will be less brown, but when the soda has been used the peat should be washed in water until the water does not become dark brown.

Peat should never be used together with sand or gravel. Simply add sufficient amounts of soaked peat to the tank and soon the material will settle on the bottom. Plants are kept down by small stones placed on their roots.

By the absorbtion of various waste products the peat may become so saturated by these compounds, that a regeneration of the material be needed. This is done simply by a treatment with soda as above for at least one week and washing of the material, but often it is even better to place all used peat in a large vat and to add sugar. If the vat is large enough, there might be much water above the peat-layer and Daphnia are produced [naturally after first adding a starter culture] with very fine results in this water, particularly if an air-stone is placed above the surface of the peat. In this way the waste products are converted into live food and no light is needed. The water above the peat-layer should remain rather cloudy, and if it becomes clear more sugar should be added.

[In very soft water the peat may cause the pH to crash, so some care must be taken to monitor pH and perhaps buffer the water with an appropriate Ca/Mg buffer, or product such as Equilibrium by Seachem.]

[zmzfam]

Very interesting.

I'm quite confused on the first part - about the addition of sugar solution to the aquaria.

How does one counteract the effects of hydrogen sulphide?

[TyroneGenade]

Hello,

You don't counteract it as much as simply only add small quantities of the sugar so that very little H2S is produced. Also, I am not convinced by Scheel's reasoning. I think the ethanol would be grabbed by other bacteria and used to produce acetate or directly incorporated into the bacteria.

I've dosed (very inacurately) my 250 L planted tank and have not detected any H2S. The water did go a bit cloudy so I guess the bacteria liked it a lot. The plants look nice though and the fish and shrimp are all still fit and healthy.

I think the best is simply to experiment and see what works.

tt

[superbole]

Hi Tyrone

Are you therefore suggesting that peat be used as a substrate as opposed to gravel or sand? Is this for killie tanks or for community tanks (or both)?

I have some Notnobranchius korthausae eggs that I will be hatching soon. I was wondering if I had to use peat as a substrate and plant the tank quite well with Java moss and Java fern, would there be a good chance that some of the eggs would hatch and the fry survive without me having to harvest the eggs? I know that kothos are annuals, but I have read somewhere that korthausae eggs can eye up in water and hatch... so I was just wondering...

Thanks,
Sheldon

[TyroneGenade]

Hello,

Scheel used the peat as substrate in which he planted plants (Hygrophila sp.). I would NOT sugget it as a substrate in a Notho tank. While some eggs may develop and hatch in the tank, sand would be a better choice as it allows more oxygen into the substrate which the eggs need to devleop. Peat, as a substrate, would not allow this. It would also grow acidic, which may kill the eggs.

Regards

[superbole]

Great thanks for the advice Tyrone. I'm going to go ahead with the river sand substrate then.

Sheldon

[hobbit6003]

Tyrone,

After reading the part on peat as a chemical compound remover, it suddenly dawn on me that I've gotten spawning peat in tanks that I'm treating the fishes with velvet, using FMC!

No wonder the bluish tinge in the tank seems to clear quite fast with peat in them.

However, whilst the fishes get well all the time, I've never bothered about the efficacy of the drug under the influence of the peat. I do, however, have to dose twice a day, and the fishes usually gets well after the 6th day, although treatment is continued for 10 days.

The good thing is, I don't think the medication had any significant effect on the eggs, as most of them collected under such condition went on and develop, and hatched out healthy.

Sorry for this side tracking!

Kenny

[wcknight]

On preparing peat for use, I've noticed that some recommend boiling the peat for several hours (up to 5 hours) before use.

Rather that tie up our range for several hours and risk being toss out on my ears by my wife, I decided to boil the peat for 10 minutes, strain and pour off the excess water, and repeat boiling. I did this three times for the Australes tank, and will reboil 5 or 6 times for the Nothos.

My theory is that like a tea bag, after several times at steeping in boiling water, the tea is eventually used up. I can use a tea bag once or twice but by the third cup, the tea is way too weak.

By reboiling, pouring out the liquid, and reboiling I figure most of the compounds will be diluted. By the third boiling the liquid is no longer dark brown but is much much lighter. By the 5th or 6th, it should be much lighter still, and instead of taking several hours, I only tie up the stove for about an hour to an hour and a half,

For some reason, the wife does not like the idea of boiling dirt for prolonged periods of time on her range.

[whuntley]

On preparing peat for use, I've noticed that some recommend boiling the peat for several hours (up to 5 hours) before use.

snip...

For some reason, the wife does not like the idea of boiling dirt for prolonged periods of time on her range.

I have found that just bringing peat to a boil (I use the microwave to do a pellet at a time) and doing a long rinse in a fishnet under the cold tap renders it just about as inert as all that boiling.

Boiling expands the air in the fibers, so water gets drawn in on cooling, letting it sink readily. The cold rinse exposes the peat to the divalent ions in your tap water (Ca++ and Mg++) so the monovalent ions like sodium (Na+) and ammonium (NH4+) are mostly exchanged out and the chemical activity of the peat is greatly reduced.

Pellets and most baled peat contain lime (though there is no requirement to put that on the label here) so the boil and rinse remove all that, too.

I, too, used to stink up the house with a long boil in a spaghetti pot. I cannot tell any difference from what I'm doing now, in the reactivity of the peat. Both methods remove that initial burst of ammonium that can be a killer if your tap water is a bit too alkaline.

Wright