Quick Question

tom_os · Feb 7, 2009

i was just wondering if i was to go to my pond and fill up a bollte with the water and collect some little daphnia things, then keep them in just a 2l bottle would they survive so i could feed them to my fish without killing the fish?

thanks

WILDER · Feb 7, 2009

A link to daphnia.
http

/www.skepticalaquarist.com/docs/feeding/daphnia.shtml

OldMan47 · Feb 7, 2009

Daphnia are easy peasy. All you need is a suitable container, some fairly hard, high pH water, an air stone and a starter sample. For food, I mixed some soybean flour and brewers yeast in roughly equal amounts, then added in about 15% finely crushed spirulina flake food and about 5% paprika. I put the concoction into an old spice jar, the one the paprika had been in. A couple of shakes twice each day and the daphnia take care of the reproduction. My 3 ounce shaker of food looks like it will last most of a year so I have far more food for these than I can ever really use. I made up a quart jar of it, not knowing how much I would need. The 10 gallon tank they are in gets a weekly water change of about 25%. When doing the water change I run the water slowly through a brine shrimp net and take what I strain out to go around feeding my fish. I replace the water with water drained from a fish tank so that the daphnia are never even exposed to typical dechlorinated water. Daphnia can be a bit picky about water quality.
Normal harvesting is done every few days by using a regular fish net. The net is coarse enough that the smaller daphnia slip right through but the adults are left in the net. The smaller ones become my breeders until I remove some again a few days later. If the number of adults looks small to me, I don't harvest for a few days and their numbers bounce right back. I get there once in a while by overusing them as food.
The breeding colony looks like this today and I am going to harvest a few later for my fish.

tom_os · Feb 7, 2009

ok thanks, so you feed these to proper sized fish, not just fry.

also do you do it in a glass aquarium? ideally i would just like to do it in a bottle with not much effort involved.

OldMan47 · Feb 7, 2009

I have been doing it in a 10 gallon tank. I get enough daphnia from it to feed most of my other 15 tanks a treat at least once a week each. A smaller container would work if you don't need as many daphnia for food.