Black snails

[Alycia]

Hey all!

I need some help... I upgraded from a 5.5G nano to a 37G about 2 months ago. When I had my 5.5 I noticed a lot of black and blonde snails that closely resemble terrestrial slugs except for a tiny, very hard, shell. They reproduce like crazy... I tried to remove as many as possible before putting my live rock from the 5.5 into the 37 (didn't think to dip the live rock though because I was being a newbie) and now they are EVERYWHERE in my tank! The majority of them are tiny, about the size of a pinhead, but nevertheless, everywhere. I have no idea what to do. I don't want them to over run my tank like flatworms might. Has anyone else seen these before?