Snails, snails and more snails!

I don't mind the snails but I am at a loss as to how they got here.
I do have live plants but they are over a year old and I have not added any new ones. I have also not added any new decorations, new fish or new substrate (I only have sand).
Can snail eggs remain dormant? I did have a single adult snail about 4 months ago but it died.
My water is on the cooler side (72 degrees). I only have a gourami and 5 bottom dwelling catfish and an unknown flat algae eater in the tank.

I went to feed them tonight and there is an explosion of snails. Most in the water, some out of the water (image 7431). Most are tiny and consistent in size while there are a few larger ones (image 7432).

Any guesses?

They come in on plants and are a small species so a few little ones in the tank can easily hide in the plants and you don't notice them until months later when they have bred a few times. If you don't want them or have too many, squash them.

Plants are over a year old as mentioned. So they didn’t ride in on plants unless they can remain dormant for long periods of time. I don’t have gravel. I did not add any decorations or new fish. Hence why I am stumped. Any other ideas?

Hi,

I had a tank in storage for 5 years.

Only 2 months ago I set the tank back up. I was cycling the tank & no fish or plants had been added.

Low and behold 2 week slater there were aquatic snails. I counted about 30 of them. I removed them from the tank but some were still there. Anyway once I added the fish they all disappeared.

Do assassin snails really get rid of pest snails? If so, any down side to using them?

gwand said:

Do assassin snails really get rid of pest snails? If so, any down side to using them?

Click to expand...

Assasin snails certainly got my tank cleared, put 10 in a 300lt discus setup, they also eat missed food and fish poop.

Delboy50 said:

Hi,

I had a tank in storage for 5 years.

Only 2 months ago I set the tank back up. I was cycling the tank & no fish or plants had been added.

Low and behold 2 week slater there were aquatic snails. I counted about 30 of them. I removed them from the tank but some were still there. Anyway once I added the fish they all disappeared.

Click to expand...

Delboy50, that is what I am thinking happened here! Somewhere there were dormant eggs and the conditions must have been just right. Thanks for the response!

Looks like you've got some Gyraulus or a relative (very small flat genus of Planorbid). Planorbid eggs can't sit dormant with the possible exception of being kept in cool water to slow development a bit relative to what it would be at tropical temperatures. If the eggs dry out or aren't otherwise in the right conditions to develop, they die. Those also look to me like adults of a small species, not hatchlings of a larger species. Most likely they were hiding around in low numbers on the plants unnoticed and you're seeing them now because things were disturbed, and they're looking for other food than whatever they were eating while remaining hidden.