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Old 16-02-2011, 06:57 PM   #2
jest1081
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Dos and Don'ts

This section is intended as a reminder of things to remember and a precaution against simple mistakes people often make without realising it.

DOs

Do make sure you age your tap water and have a good idea of what's in it:

If it contains chlorine (chloramine will also put chloride into the water), it must be left to stand or aerate the water for 24 hours to drive off the chlorine gas (fluoride is usually very low in concentration and isn't really something to worry about).

If your water contains lots of ammonia, this will inhibit the population growth of your culture - again, aerating the water vigourously helps drive off ammonia (although it takes a lot longer than with chlorine).

Any metals in the water can often be toxic to daphnia. Some can inhibit population growth (see the section on Physical Requirements).

Do carry out regular partial water changes.

Do feed regular modest amounts of food (this will depend on the culture size).

Do make sure you have adequate water hardness for your daphnia, otherwise they will not reproduce at a high rate, and will probably just produce ephippia.

Do try to maintain a constant temperature (about 20oC is ideal for most species).

Do cull/harvest your cultures at least once a week to avoid overcrowding.

DON'Ts

Don't wash your hands with soap/detergent just before you put your hands in a daphnia culture unless you've _thoroughly_ rinsed your hands because soap and detergents are toxic to daphnia.

Don't overfeed - if anything, underfeed your daphnia to avoid fouling and toxic build-up of ammonia.

Don't put your daphnia in a container of dense algae (and don't change too much water from the tank for algae water at one time) because algal blooms tend to raise pH to very high levels (over pH 9), and coupled with even a low ammonia concentration, this could be disastrous for the daphnia, killing them in short order. Ammonia toxicity increases with higher pH.

Don't keep all your eggs in one basket (or daphnia in one container). Even the best of us will have accidents on occasion or have an emergency, etc, and our cultures may be poisoned or die off for no apparent reason. To counter this, it is best to seed as many water vessels, aquariums, and even flower window boxes with daphnia when the culture is first obtained. This will ensure you will be able to "restart" without too much fuss.

Don't use insecticides near your daphnia containers, and don't leave your daphnia container in a room that was just painted/varnished/etc, because the fumes/gas can be toxic, and even if it doesn't kill the daphnia, the fish you feed them to may be slowly poisoned.

Don't use airstones in a daphnia culture. Use an open airline tube or a bio-foam filter (the latter contains an airstone inside in the apparatus, but the bubbles are not fine enough to harm the daphnia when the bubbles emerge into the tank. Note however, there should only be a weak flow of air through the filter to avoid too much water flow).

Don't add miracle grow, etc, directly to the culture. It won't be much use, and it could also poison the culture, in high concentrations.

Don't add fresh tap water to a daphnia culture unless you want to kill them all with the chlorine.

Don't keep your daphnia in the dark for days at a time as this can stimulate them to produce ephippia.
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