White worms are one of the easiest and best food to culture for feeding to killifish but are just as suitable for all freshwater tropical fish. They do not suffer pests like grindal worms do, the cultures don't stink and rot like fruit fly cultures, they don't require water like daphnia or vinegar eels, and unlike earthworms they are a near perfect size - every adult killi known can handle them from Diapterons to full grown gularis

Convention wisdom and decades of aquarium literature says if you feed your fish white worms every day then they will almost certainly become fat; whiteworms are a fatty food. I don't doubt people have had problems with them, but I have not. Typically we are told to feed white worms bread soaked in milk and one has to wonder how natural of a diet this is - do worms really eat wonder bread and butterfat in the wild? Probably not, so, I tried feeding other things to my whiteworm cultures such as pumpernickle bagels and carrot shavings and spirulina. Thus, I began feeding my fish only white worms to see what would happen.

So I fed white worms and I waited. I waited for all my fish to bloat up and die, but it never happened. They were fine. If anything they were not as fat as usual adult killies, they never got that slighter-larger-than-wild-type build that older tank raised killies seem to get. Hmm...

White worms are comfortable at 60 F / 15 C and do not do well at higher temperatures, even if they survive them at all. If you do not have a cool basement or a spare fridge then you may lose your culture over the summer in a warm climate; when I lived in California I never met anybody keeping white worms, although grindal worms, which can take warmer temperatures but are a bit smaller, were fairly popular. When I moved back on the east coast, white worms seemed to be one of the more commonly cultured food items.

They are cultured in mix of half potting soil half peat moss in a shoe-box sized container with a lid that's fairly tight fitting to prevent loss of moisture through evaporation, but not tight enough so they'll be deprived of oxygen. As the culture becore more and more successfull move it on up to a larger sized box. Sweater boxes work well and whatever that next size up it that's 1 x 3 feet. You can raise a lot of worms in one of those this no odour or make noise but can feed a LOT of fish.

The medium should be moist but not wet. It should never be dry. If you get it too wet the worms will cover the surface of the soil to escape drowning, and food can rot very very quickly under these conditions. If that happens you can see what I call "crazy worm syndrome" where all the worms try to leave the container any way they can. You'll find them on the underside of the lid... everywhere except in the soil. If this happens start a new culture immediately from the worms you have left. They will die very quickly in the old culture (which is why they're trying to escape) and many may be dead already. You[ll know right way by the smell when you open the bix how many are left. This is why you have several cultures going at one time. You can't reuse the bad culture until you've let it dry out in the sun a bit and you've removed whatever is rotting. Once it no longer stinks and has dried out you can reintroduce some worms and you should be ok.

I used to remove worms from the culture with glass. On top of the culture place a piece of clear glass about 1/3 the size of the surface are, the worms will congregate under that and can be removed from here with your finger and dipped into a tank. place the food under the glass, this encourages them to congregate there to a greater extent. But once a culture gets good enough you can usually time is so that when the worms have all but devoured the food you can pull a handfull out leaving the food behins. These are placed in a glass of cold water (hint: keep a box of 100 dispoable glasses in your fishroom. If people you share the hosue with find a drinking glass full of water and worms you may be seeking new acccomidations suddenly) and rinsed and decanted several times. They'll live for nearly a day in the tank and while they will busy themselves, they don't dig in quickly like tubifex and aren't nearly as disgusting as "black worms".