well I tried it today. got me some snails and put them in my 5 gallon and 20 gallon tanks. love the little guys so I thought I would give it a try in my 90 gallon (with the loaches)
it all started out very nice. I put the tiger snail (nerite) in there on one of the boats. everyone just swims around like nothing is happening so I think this is going to work out. he moves around and starts doing his snaily thing. then I look over there and one of the loaches is just bugging the heck out of him. I wonder what he will do - will he give up and leave him alone? no... he knocks him off the boat. ok, so then he leaves him alone. I think ok, we will see how it goes from here. so the loach goes his way and eventually the sail comes out and starts snailing again. then the stupid little loach comes over and does it all over again - until the snail lets go and pulls in. then the loach leaves. well, that was enough for me! the snail is no longer in the 90 ... so the moral to the story? tiger snails and polka dot loaches (at least in my tank) do NOT go together