The thing is, I'm not even feeding anything in my tank at the moment. I just set it up not even 4 days ago and noticed a few white snails. Then I woke up this morning and saw that there were probably 10-15 in the tank.I personally like snails in my tanks. They do a great job on cleaning up dead plant matter, eating algea and turning the substrate. I actually add calcium to the tank to help in their shell development.
If you snails are going from few to many in short period of time, then most than likely you are over feeding the tank. If you cut back on the amounts your fish are being feed this will help control the snail population.
At this point you may want to remove some from your tank if it is becoming over populated with snails. But IMO I would not irraticate the entire population, because of the benifits they provide.