Malaysian Trumpet Snails missing, other snails fine

[Chessolin]

In my guppy tank (26 gallon fresh hardwater not planted), I had hundreds of snails. Probably 95% of them was MTSs. They were everywhere, they climbed the glass and died stuck between the rim and lid, got in the filter, hung upside down from the water tension, and descended on any food that sank to the bottom.

Then one day I noticed that they were almost all gone. The ones I can see on the gravel aren't moving. The pond/bladder snails and ramshorns have basically had the tank to themselves. I dropped some algae wafers in last night and turned off the lights two hours later, they were barely touched, just being nibbled by some ramshorns. There was one MTS on the glass.

What can affect MTS but not pond and ramshorn snails? Are they just hibernating?

 

[dougall]

Obviously something changed to cause a problem.

did the temperature of the water/aquarium change? the snails are tropical, I don't think that they would hibernate and they need higher temperatures than pond and ramshorn snails.

 

[Chessolin]

Temperature is the same. I added Seachem Equilibrium to make the water hard but I did that before. I think it was after a water change but I don't remember. All I can think is I might have forgot to add declorinator to the bucket before I poured it in but I added it to the tank about 5 min later. Our town recently started coordinating the water. But wouldn't that have hurt the other snails too?

 

[dougall]

different species can be more fragile than others,

I assume no other water parameters changed, assuming you are monitoring them. I doubt it could be forgetting the dechlorinator for a few minutes, but anything is possible unfortunately.

hope some of the remaining ones turn around and get back to normal.