The only way to completely get rid of them is to have a snail eating fish in the tank, most loaches will eat snails, so one of the smaller species is an idea if you've got a small tank. I've heard dwarf cichlids eat snails too.
If you dont want one of these fish, then snails are often a sign of over feeding, in which case just reduce the amount you feed and that should at least prevent them getting out of control.
FYI did you remove the bodies of the ones you squashed? Probably best to if not as the decomposing bodies will introduce lots of nutrients into the tank and could cause algae.
Sam
Don't squish them, you want to remove them first that way if they are carrying any eggs they won't be released as for snail eating fish it would depend on the fish, some would only control it and some would exterminate all of them, best way to get rid of them all is just to strip the tank let dry for two days and set back up.
Bleach 1:19 ratio, 30sec. not 2-3min.
30 seconds is probably too short IMO. 2-3 minutes for most plants is fine but for the more delicate then 1.5 minutes. I know because I've done it many times myself (along with many others) with no problems. Some plants do take a slight 'hit' but soon recover. Some people even recommend 5 minutes but I would think that this is too long.
James
Ya guess you could, last time I tried a minute and haven't discovered any problems, though don't do any less than 30 sec. since my friend did 15 sec. and he had snails.
this is what i wrote on aHow to prevent getting Pest Snails
Preventing pest snails from getting into your aquarium can be a difficult thing. They most commonly come in on live aquatic plants from online, petstore, or even from a friend. Sometimes the people giving them to you have no idea there are snails, but most commonly they just can't prevent it. You also have to be aware of snails when buying something from a stores fish tank or friends or online that has been in contact with the water ex. heater, filter, gravel, ornaments. Most of the time you can control your snail population by feeding lightly and vacuuming your gravel throughly.
Prevention
WARNING: HANDLE BLEACH WITH CARE! PROTECT YOUR EYES WHEN HANDLING AND WASH YOUR HANDS VERY WELL AFTER DONE HANDLING IT
The most common way to prevent pest snails from entering your aquarium is the bleach method. This method is a simple dunk your plant in a bleach bath to kill the snails.
Steps
1. Take your plant out of packaging/bag and have it ready nearby
2. Get a bottle of normal bleach, try not to use the scented and other varieties
3. Prepare a 19:1 ratio with 19 being water and 1 being bleach in a clean new container (I find it better just to buy a small cheap Betta bowl and use it strictly for bleaching plants
4. Rinse your plants under running tap water and rub your fingers over the leaves to remove all snails and eggs as possible
5. Now take your plants and completely submerge them in the solution for 30 seconds (some say 2-3min. but I've done 30 seconds since this was what I was originally told and it hasn't failed me yet
6. Take plant out of solution and rinse well under tap water
7. Let plant soak in de-chlorinated water to remove all traces of bleach
8. You can now plant your plant
Another, more simple but not usually as effective method is to buy your plant, rinse it off and remove all visible snails and eggs and plant plant in separate tank just setup for checking to see if there are snails on your plants
WARNING: ANARCHIS CAN NOT BE BLEACHED AS THE BLEACH WILL KILL IT
. Rinse it under tap water and get rid of as many snails and eggs as possible and plant in aquarium at your own risk.
Getting Rid of already established snails
Once already established snails are rather hard to get rid off. Before you decide if you want to get rid of them you need to decide if they are pest snails or Malaysian trumpet snails
http
/www.aquahobby.com/gallery/e_Melanoi...tuberculata.php. These snails help with cleaning your gravel and getting rid of unwanted air pockets in sand and are valuable snails to have in the tank. Other small snails not looking like these are usually pest snails not attractive to have in your aquarium. Usually when you have a snail population explosion it is due to overfeeding and having leftover food present. The snails feed largely off of uneaten food. Here are some ways to get rid of them
1. Use a chemical product such as Had-A-Snail WARNING: these products usually contain chemicals that are harmful to invertebrates and sometimes fish (I would advise not using these but it's up to you)
2. Put a piece of lettuce, cucumber, or other green vegetable and leave it over night or until you see lots of snails on it then remove it and replace with a new one to remove snails
3. Simply kill all snails you can see (usually doesn't work)
4. Stop feeding so much
5. If your tank is large enough get a clown loach(require I think 75 gallons minimum) or other type of snail eating fish
6. I personally have not tried this but I would think if you didn't feed for 5 days and kept sticking lettuce or cucumber or some other vegetable the snails like you might starve them enough to go to the vegetable and remove them. You could also feed your fish live food or flake and only what they could consume without leftovers
7. Remove all plants, all decorations, heaters, thermometers, and filters from your tank. Let all ornaments, heaters, filters, etc. sit out until they are completely dried to kill all snails in them. If you have another tank without snails take some of that filter media and stick in your dried out filter and get rid of the old media in case it has snails. Bleach all live plants as described above. Do a large water change, take out all snails visible, on wall, and in gravel. You can stick a airstone in and cover the tank with a blanket/towel to keep water moving and heat in while they are drying out. After filter and heater are all dryed out put them back in tank but not ornaments. Leave the tank as bare as possible and feed very minimum amounts removing all snails as soon as you see them. After a week of no seeing snails wait a month and if you get no more snails you have gotten rid of the snails, but if you see some again wait another month starting from when you last saw one. (I used this method for one of my tanks and it has worked but you must be patient and let your tank look like crap for awhile to get rid of them for good)
8. The most drastic way to do it is put your fish in another tank and clean and dry everything out and setup your tank again from scratch, if you do this make sure you have filter media from another tank so your tank doesn't go through much of a cycle again.
9. Use any combinations of above listed steps
Remember snails can be good if kept under control which can be done by not overfeeding and removing unwanted ones weekly. nother site don't know if it's helpful or not
Definately agree with Andy, we should post this

Good idea Andy
Sticky it
atm