Scavengers compatible with planted tank

This is my first posting to this list, so pls be gentle.

I'm new to planted tanks and would like to know what bttom feeding scavengers are compatible.
I have crayfish which seem to be chewing on my foxtail. Also, I've read that snails will tend
to uproot plants, and that plecostomus may eat my Amazon Sword plants.

Any suggestions on what botom feeding scavengers, especially those that may eat fish waste 
would be greatly appreciated. You may mail me directly if you wish.

Thanks, Paul Robertson  robertp at h01_pgh.wec.com