I have a 10 Gal Aquarium and inherited some pond snails when I purchased some live plants. In 3 weeks, I went from having just a few, to a population explosion. Everything was fine until 2 days ago when I noticed that the snails looked very inactive and now I cant see a single one! I suppose they have buried themselves in my gravel, but why? Is it a temperature or water quality issue?? I know they haven't been eaten because there are no empty shells, and my guppies never have seemed interested in them. What going on here?

Also, how do these snails deal with adding aquarium salt. I have heard it is good for guppies and mollies, but will it affect these snails adversely?

I would dig around in some of the gravel to see if there are live or dead snails down there. Regular pond snails don't spend much time down in the gravel unlike Malaysian trumpet snails who stay down there all day (and come out at night). Have you checked the tank at night with a flashlight to see if there are any snails coming out then? Guppies can eat snails but probably not as many as you must have had since you said you had a population explosion. Snails can have die offs but then you should find their empty shells all around. As far as I know, poor water quality or temperature changes won't make pond snails dig into the gravel. They will be slower and eat less when it's cooler of course.

Snails can tolerate some salt. A tablespoon of salt per 5 gallons (which I use in my tanks) if fine. More will make the snails uncomfortable. I'm not sure at what level they would start to die. Guppies like some salt while mollies like a lot of salt (even a few tablespoons per gallon which snails don't like).

I checked in the gravel and there are quite a few dead snails down there. THere are about 4 living snails left, and they happen to be the largest ones. They are moving around now, but not at the fast pace like before the die off. They are sluggish and hardly come out of their shells. I am wondering if the polulaiton could have been infected by a parasite or other disease? About 2 days before the die out, a new fish was introduced to the tank and the water from the pet store he was transported in was unfortunately dumped in our tank. Could a parasite like that have been waterborn? Nothing other than snails have been affected as my fish are all healthy, a guppy has even dropped about 20 healthy fry, so I dont think it is a water quality issue. Anyone have any ideas?

Most fish and snail parasites are specific to those species but a few may affect both types of animals. It's possible that you introduced something but finding out what that might have been would be very hard and require microbiology, microscopes, bacterial cultures, etc. Since you had a few survive, it's likely that they managed to overcome whatever happened and should hopefully recover and breed more of them.

Have you tested the water quality? It's a good idea to check pH, hardness, ammonia, and nitrite when something seems wrong. You may find nothing but, if you do, it can be fixed.

With all those dead snails in there, I suggest a good gravel vacuuming and 50% water change every week at least until the bodies have decomposed. I know when my trumpet snails died off from a parasitic medication, it was really impossible to remove all those little dead snails. They don't suck up into the gravel vacuum so they have to be removed by hand. The dead snails may cause an increase in the ammonia and/or nitrite levels as well as promote the growth of bacteria and fungus feeding on them.

I hope things are fine from now on!

Hi,

you know, most of my pond snails have died too. I also have apple snails in that aquarium, and they did the "cleaning part". When one of the pond snails died, the apple snails found it very quickly, and eat it. So the water stayed clean.
I know it's not quite the help you might be looking for, but it solves the water-cleaning problem.

(By the way, in my aquarium, only the small pond snails have survived...)

keszi
from Hungary