Fishless system?

[Beverly]

I had a fishless BB 37g monti cap tank for several months awhile back. It was great. No fish to feed, but there still seemed to seemed to be some crud accumulation, I suspect because there were probably hitchhiker crabs in the rock. I also had 2-3 snails in the system. IIRC, there was also a bit of film algae on the glass, so we still did weekly maintenance on the tank. For good coral growth, alk, Ca and Mg all have to be maintained, though I'm sure you're aware of that

Here's a pic: