We have three crabs in a ten gallon. We're probably upgrading to a 20L later this winter.
My question: how do I add more substrate when I always have at least one crab dug down? Just a handful at a time and wait? They're in a very dark corner of the house that gets no natural light, so I have an aquarium UVA fixture that goes on/off on a 12 hour cycle. The biggest one comes out about an hour after the light goes out. The others usually only come out in the middle of the dark cycle, which is about 3am for us and I'm not going to play crabitat-reno when the kiddo is asleep in that room.
They've only got about 4" at the deepest and it's compacted a bit with our "trying to figure out humidity when the furnace kicks in". I don't always know where they've actually dug down or tunneled and I don't want to cause a collapse.We use EE. I might do a sand-EE mix later this year, but our only local playsand is silica sand and I didn't want my young kids to help mix that.
