I'm culturing live black worms in a 10 gal
tank with 2-3 inches of water and a small (smallest size available) sponge filter. I try to feed them every week with the mulm on the bottom of my guppy tank, and the filter is there to filter the water and provide aeration.
Like any aquatic animal, they can drown if there isn't enough aeration (dissolved O2
) in the water, even if they are fully aquatic. Imagine us having air but no O2
on land. Same story, different situation.
They require large amounts of dissolved O2
, so I'd recommend either a sponge filter (2-in-1) or at least an airstone, and you can keep it at room temp and they should do fine.
One more thing, I have a thin layer of 1/2" gravel because they'll get split moving through it and I've read that's how they "reproduce". Just something to consider.
Hope this helps!