Yes, I think il get a couple of snails n put them in the small tank.
Do they need the same 'treatment' as the fish? By that I mean do i use filter n heater etc etc like with the fish? (hee hee it reminds me of times as a little girl collecting cockles from beaches. I remember carrying them back to the house in a bucket and leaving them in my bedroom. Coming back hours later to observe them and finding them all over the floor up the walls and on the bed!!

)
Anyway, erm, my next query is type of snail? Iv only seen Apple snails in the shops near me. Would they 'do the job'?
Ta
Kaz