Have you noticed a lot of snails in your aquarium? Not sure where they came from? While often harmless, there are some species of snails in aquariums that can multiply to such great numbers that they become a bit of a nuisance. They can hitch a ride on live plants and can even sometimes be accidentally added via water and nets used in catching and transporting fish. While it may not be possible in some cases to completely eradicate the snails in question, there are many steps one can take to reduce their numbers.
Usually a snail population explosion is preceded by overfeeding your fish. All of the uneaten, extra food fuels their growth and leads to more snails. By simply reducing the amount of food being offered or removing any uneaten food in your aquarium, you can leave less for the snails to munch on. While you will be unlikely to completely starve out your pest snails this way, you will avoid excessive reproduction.
Removing snails via traps can help keep the population in check. The concept for most traps on the market is fairly simple; bait food is used to lure them in where they can be collected and physically removed. Usually leaving these overnight does the trick. You can also place small pieces of lettuce in your tank to attract and remove snails, but you should be careful with this method as lettuce left too long in an aquarium can rot and cause other problems. With any trap, you will have to set it up on a regular basis to sufficiently remove snails enough to put a dent in the population.
In nature, there are creatures that will prey on snails. So, it makes sense that if you have a snail infestation, you might just want to add a critter that will dispose of your snails naturally. Traditionally, pet shops will recommend animals such as loaches and pufferfish. Puffers, though voracious snail eaters, simply do not go in most community tanks. You can set up an extra tank with a puffer and feed it snails from your main tank, but that means you would have more tanks than perhaps you intended. Loaches can be a great option, but they too are not always the best community tank inhabitants. The best snail eating loaches are in the genus Botia and can be quite aggressive and get fairly large (8-10”). Some more peaceful loaches such as kuhli loaches (Pangio sp.) or hillstream loaches won’t touch snails at all. Probably the best biological control animal for snails is… another snail. The assassin snail (Clea helena) will hide out and ambush snails slowly over time. Eventually, you will have almost no pest snails. You will, however, have a population of assassin snails. Thankfully, it’s a fairly attractive snail in its own right and does not reproduce nearly as fast as bladder snails, ramshorns, Malaysian trumpets, etc.
Whenever possible, reducing the chances of introducing pest snails will go a long way towards reducing chances of infestation. Dipping all live plants in a 5% bleach or salt bath or buying tissue cultured plants can decrease chances of accidental introductions. Also, discarding all water from acclimating fish and being careful not to net any snails that might be in the bag with the fish into your aquarium can help.
Like most issues encountered in aquariums, approaching a solution from multiple angles is the best. By reducing snail introductions, not overfeeding, trapping and removing snails, and introducing biological control, you can often keep snail populations at bay. Of course, keep in mind that a few snails here and there won’t harm anything, so try not to sweat the little things.
https://blog.tetra.net/en-en/helpful-carnivorous-snails/ A helpful guide by Tetra about keeping assasin snails
https://en.wikipedia.org/wiki/Botia A brief Wikipedia overview of some botia loaches