on snails...
buying one snail does not mean that no more will appear, unless you are talking about the big snails like apple snails or mystery snails...
the smaller ones are mostly asexual, they can make themselves pregnant and lay eggs
so is this a bad thing, i think not, as the snails (the smaller ones anyway) will eat almost exclusively on algie, and uneaten fish food, they will die off if there is not enough food for them, so they will only take over the tank if you over feed, snails are you friends, and they are a great way to tell if you overfeed,
if you want to get rid of them, looking for eggs is the hard way, taking them out of the tank as you see them is the best way, it will be a pita when you first start out, but within a month you will only see one or two a week, then none at all
on plecos- yes a dirt pleco is going to get way to big, and they are poop factories, but its not the end of the world if you find yourself with one, just go to the store and see if you can return it, if not see if someone else with a bigger tank wants it.
-also make sure that you research your snail if you plan on buying a big one (the apple or mystery) although i cant think of it off the top of my head, and dont feel like looking it up for u (as u can do this) i forget wich one will buldose through your live plants... i would suggest grabbing a few ramshorns or mts snails from your fishstore, tey will probably be glad to get rid of them
