Apparently snails will survive the cycle, so I guess they should also help the cycle if you have more of them. I've had snails in a cycling 1.5 week old tank, and they're getting bigger by the day. No signs of any cycle effects on them whatsoever!
so I have a tank about 6 days into the cycle and already have nitrates showing up, the ammonia is gone and the nitrites are almost gone... should I throw my snail in the tank or will it throw things out of wack?
well, I would think that if you've got nitrates, with nitrites/ammonia gone, you're finished cycling
hehe, I just read your signature, it looks like you already put them in just a warning though, they're probably too big for dwarf puffers to eat the whole thing unless they're about less than a week or so old.
I have 1 Mystery Snail and 1 pond snail in my 5 gallon, which I'm still waiting on to finish cycling. My ammonia levels are now up to 4 ppm and they don't even seem to notice! They're thriving just the same. (But I do hope it cycles soon.)