I know that this is an older post but I thought I would also add something for those that read it later like myself. I had a 20 gallon tank and have a 30 gallon tank. The 30 is without snails and I hope to keep it that way. The 30 has all my fish. The 20 is the thoroughly snail infested one even when I don't feed them at all. My tank water is high ph (about 7.8 to 8.0) and hard. That's due to my Arizona tap water. It's great for Cichlids or saltwater but not so much for fish that like the 7.0 ph range.
While I agree with some previous posters about food source makes them populate faster, they will not necessarily die out even if you don't feed them at all. Once they reach epidemic numbers, they feeed on each other but reproduce faster than they eat one another. So try to stop them early on from existing or it might be too late later. Here was my experience with them.
I moved all my fish from the snail infested 20 gallon to the new 30 gallon tank and was about to use some harsh chemicals to kill off all the pond snails in the 20 gallon. I don't have live plants (only artificial ones) so I could use anything on them. But I saw the info somewhere on the web about using loaches or Assasin snails to kill pond snails. I thought that would be a better solution and have some happy fish to feed them to.
Tried clown loaches 1st who had absolutely no interest in the snails at all and just got too big for my tanks and were eventually given to friend with a 55 gallon tank. They didn't eat even one snail.
Next, I tried Yoyo loaches. They were very hard to find here and cost a pretty penny. They also showed no interest at all in the snails. I've since moved them to the larger uninfested tank. They also never ate a single snail that I saw. They also are escape artists. They love to jump and can find a 1 X 1 inch hole in the top and jump out. Had to loach-proof my tank top.
I finally introduced 10 Assassin snails to the infected tank. They are almost never sold here. I had to get them online and each of them cost more than I would pay for most freshwater fish. Immediately, the pond snails attacked the assassins in mass, killed and ate all 10 of them in 2 days. All that is left of the Assassins is their colorful shells. About 20 or so pond snails would attack the Assassin snails as soon as they were found. Felt really bad about sending these Assassins to their death. They never had a chance to eat any pond snails as the reverse happened rather quickly.
When the pond snails get hungry and there is not enough food left, they prey on one another. It's not uncommon to see a gang of them climb onto the shell of another and literally pin him and eat him. When I stopped putting food in the tank, they preyed on each other. Too bad it's not like the Highlander "There can be only one!" scenario. They repopulate faster than they eat each other.
So going back to my original plans for the chemical means of eradication, I put large amounts of salt in the tank. Salt in large quantities had no effect on the pond snails I could see after two weeks. I drained that water out and added two different kinds of snail killer chemicals with copper sulfate and frankly overdosed the tank on purpose. About half the snails died over two weeks but the population came back strong after I quit dosing a month later.
Finally, I just drained the infected tank and threw out the artificial plants and gravel and ornaments. I had been using an older cheaper hanging filer and just discarded it too as I noticed snails and eggs were inside it's parts too. Used a razor blade cleaning tool to scrape any eggs off the glass walls of the tank. I washed the empty tank with scalding hot water. I let it completely dry out and left this empty tank in storage about a month. I decided to set it up as a platy tank a few days ago. Within 2 days of adding new gravel/filter/ornaments/artificial plants, I saw 20-50 little baby pond snails. I squashed all I saw but now it's back to about a hundred small pond snails. They are not being fed at all. There were obviously some eggs somewhere I missed in a tank lip or something. I finally just gave up, drained the tank and again purged all inside it. I broke the tank walls so no one else tried to use it and threw it in the trash.
I got another new 20 gallon and started it with all new stuff. So far no snails in my 20 or 30 gallon now.
Moral to this story is once you are infected you may never completely get them out of your tank without purging every infected item like you were dealing with a plague. Certainly don't take them to a pond or stream or just what you add there could destroy a whole ecosystem. These are the best surviving creatures I've ever seen. Some little Noah's ark collection of eggs would always survive.
I did some reading about them. Their egg sac gel can dry out completely and still the pond snail's embryos can hatch years later when water is applied. Two ponds snails can produce over 50,000 little ones in their less than 1 year lifespan and can completely lay eggs and therefore reproduce every 2 or 3 days. The eggs seem to survive almost anything.
Don't wait if you see only a few. Kill them all why you can or you'll have huge problems a few days later, whether you overfeed or not. None of the eradication methods worked for me.
Last edited by Graystone55; 04-27-2015 at 07:47 PM.
Reason: Grammar bad