There are commercial snail-o-cide products at most pet stores. Read directions carefully regarding usage in a planted aquarium. I have heard that you can float lettuce which will attract the snails. Clown loaches love to eat snails. What are you putting into the aquarium to feed the plants? Without fish, you may wish to supplement the water with CO2 and there are additives available for ferilizer as well.

Loaches are a great way to control snails. I had hundreds in my indoor pond [130 gal] and now have only one very fat Loacha loach.

Dont use the snail rid products at all, they will kill myour plants.Check out this article

Here is a link that might be useful: snails

Some bettas are also great snail-eaters, but that depends on the betta. Cichlids, too. Can you describe what sort of snails they are? I'm assuming their the football-shaped kind.

Thanks for all of your ideas! I only have one fish now, some sort of bottom feeder to pick up the trash at the bottom. I'm using some sort of fertilizer/food for the plants once a week. Seems to be doing well, they're taking over. I'll try the lettuce thing. How large to Loaches grow? I'm not sure I know much about them. As far as what the snails look like... their shell comes to a point. I'm not sure what "football snails" are but that sounds like something it could be. I've also tried the betta - he paid no attention to them.

Regular pond snails then, which is what I expected. I wanted to make sure since some snails are resistant to different eradication methods.

Clown loaches get very large unless you stunt their growth, which I think is rather cruel. Most of the smaller loaches I've read about need to be kept in groups, which can be just as difficult to fit in your tank as one big fish. But I'm a far cry from a loach expert, so you ought to go to loaches.com and research various species.

One thing I should have mentioned before is triops. You can hatch them into a liter jar until they're old enough to eat pellets, and then add them to your tank. They won't do anything about the existing snails, but they'll eat the eggs. If you then pick out the adults, I'm sure the population would drop dramatically. If you add the entire jar of triops water to the tank, you should get little microscopic buggies to populate your tank (you probably have some now, actually). These little guys will act as food so that the second generation of triops larvae will have food, and they can then keep up the good work. I do believe triops will nibble at plants, but so long as they have other foods, they shouldn't be a problem. Better than the snails anyway.

Clown Loaches get to be about 12" at full adult growth. Mine grow about 1/4-1/2" a year, sometimes about 3/4" the first year. I have never owned one more then 7 years, either traded in or gave away. I would try less ferts first. Your plants will let you know if they need them. Usually just iron and potassium and magnessium is all you need to add. Nitrate comes from ammonium excreted from fish and other "crud". Phosphates are not used largely by aquatic plants. The right amount of ferts will make less algae, thus less snail food = less reproduction. If you had plecos in your tank then it should be big enough to house a clown loach. Get at least 3 though, they are more interesting and will not hide as much when theres a small group. Oh yeah, they can last up to 50+yrs.