Also, I have a small snail that came in my plants when I bought them, r snails any good to keep? Do they do anything good/bad to the aquarium?
Some aquarists seem to have a phobia about snails. I on the other hand, and many share this view, consider them a blessing. Provided they are plant-friendly
Of the commonly-seen snails, the best is undoubtedly the Malaysian Livebearer, or sometimes called Malaysian Trumpet or Malaysian Cornucopia Snail because of the shape of the shell (long, spiral, cylindrical like a cornucopia or horn of plenty). These fellows burrow throughout the substrate, and perform a service that absolutely nothing else can equal in a planted tank. A nice feature is that they can exist in soft acidic water as well as basic hard water. Many other snails do not fare well in soft water due to lack of calcium for their shells.
The other two "good" snails are the pond snail and acute bladder snail. To me they look identical, but they are indeed different. They, like the MLS, do not eat plants unless the leaf is already dying. Both reproduce by laying eggs.
Any of the above will eat "stuff" that nothing else touches, nor can usually get to, before it becomes problematical. They also eat algae, though not to such an extent as to be very effective except under normal conditions. I view them as a sign of a healthy aquarium.
The ramshorn snail is often grouped with the pond and bladder snails as useful. Some have reported that these will eat plants, others say not. I haven't had these for many years, and don't intend risking it.
There are other larger snails that aquarists specifically buy; some are included in our profiles [second tab from the left in the blue bar across the top of the page, then under "Other Aquatic Creatures"]. It is unlikely that one of these will be introduced with plants; that usually falls to one of the smaller species.