Okay I have some kind of problem and cannot figure it out. In the past 3 weeks I have lost 4 apple snails. Just pulled another one. It started when I noticed the cloudiness in the tap water. I've checked everything in all the tanks and all parameters are normal. I've got 5 left all in different tanks but the 4 were in different tanks also. The 4 that died were my 4 largest ones the smaller one seem to be doing okay at the present. Any ideas of what I should be checking for. All other types of snails are doing okay just the apple snails are dying. These snails I've had for over 2 years without a problem.

Some chemical that you normally don't test for must be out of wack in your water treatment plant. I'd do a 25% water change in affected tanks using distilled water in order to lower the concentration of whatever the mystery chemical is.

First thing comes to my mind is copper. Have you tested for this? Also, have you tested the water straight from the tap for anything possible changes? If on city water, it's possible they bumped up certain chemicals in the water too. Dose Prime at double strength for a bit.

I'll get a copper test kit. Have been doubling Prime since the water change being cloudy.

Skip the copper test kit and just get some poly filter sheets! They pull copper and all sorts of yuckys out of the water and you really only need a strip to get the job done! It will change different colors depending on what it is pulling from your water.

I did the poly filter sheets last week in all the tanks.

Cleaned all the filters today and packed them with fiber fill we'll see.

Hmmmm got me stumped then.... What color did the poly filter turn?

green

aqua possibly?

teah I guess it was more aqua blueish green.

They have aqua to dark blue listed as copper....
I could see copper ending up in city water supply for a bit.