Hi - I've been posting a little bit for a few months, but figure I should introduce myself. I have a 20g tank with about 15lbs of live rock, some big pieces of dry coral skeletons, and an assortment of invertebrates. This all started because last summer my kid picked up a shell at the beach, brought it home, and discovered a tiny hermit crab living inside it. For whatever reason, I had to save that crab. "Happy" the hermit crab is now about 2" across and is the boss of the tank. The LR from the LFS came with a pair of blue-legged hermits (only one of whom is still with us after a dispute over a shell), some stomatellas, and a couple of freaky bristle worms. There's one gorilla crab that we've yet to catch and return, but next time we go to the beach we'll get him out of there.
We used to have a couple of asterina and brittle stars, but I haven't seen them lately. I wonder who ate them. Suspects are the bristle worms, the gorilla crab, or the snails.
Snails. At least a few were hitchhikers on LR and probably good guys. I've got a couple of big guys and a few smaller ones from the beach who turned out to be carnivorous so they're probably whelks. Next trip to the beach I'll take back the ones I can find. I don't really know what they are eating right now, aside from about once a week when we give Happy the Crab a scrap of fresh fish and a snail steals it. It does seem like I'm not seeing a bunch of small bristle worms in the sand like I used to, there are just a few big worms in the rock. So maybe the snails are eating the baby worms. If that's the case I wouldn't mind keeping one or two to manage the worm population.
I've got a big nitrate problem though, and don't know where it's coming from. I've got a Tunze 9004 skimmer, and a Fluval 206 canister I use as a reactor. Yes, I clean it weekly. I wonder about the tubing to/from the canister harboring gunk though. I also wonder if the nitrates are coming from a dead snail somewhere. The snails I know about are growing well so it doesn't seem like they're starving, but if they're carnivores that must mean there is some meat in there somewhere right?
I haven't gotten any fish yet. I need to get rid of the gorilla crab first, and get my water quality stable. Honestly I like watching the inverts so much I don't really miss not having fish. I'll add a pair of clowns eventually.