re: snails
It's a shame that the server was changed on this site. We had a great thread about nerites going for a while.
I have 10 nerites that I bought off ebay, of all places. I have had them for over a year, and they are fabulous. The y have flourished in salinities from 1.002-1.008 without flinching (do snails flinch?).
Every few weeks, they have an orgy, riding piggyback and laying large numbers of eggs
The eggs are white, glossy, 1x3mm, oval shaped but relatively flat, layed on driftwood, powerheads, whatever. After about a week, the "shell" comes off, flipping/hinging towrds one of the skinny ends. I have never seen any babies for sure, though I have many hundreds of little black dots I can see on the crushed coral mixed in with my gravel, and they definitely move. One of these days I'll take a few tsps of gravel to work and look under a scope. . .
My advice, get'em. I think they were about 10 bucks for 10, s/h not included. They are olive colored and aobut a nickle's diameter. They completely keep the algae down, with glass cleanings needed only every few weeks.
However, I must admit, the scats may be helping. . .
If anyone finds a cheaper source, please post it.
BTW, I also have a healthy population of the long, pointy snails that live in the gravel and come out mainly at night. Most fishkeepers don't like them b/c they overpopulate and are too hard for puffer's teeth. I don't have puffers anymore, and I've never ahd a prtoblem with overpopulation. Plus, burrowing in the gravel is xupoposed to be good for the maintainence of it as a filter.