FW clams

[Stingray6]

In the past I have owned FW Clams.But they all seem to die after a few months. My question is what kind of water peramiters do they need ie ph temp and such. I currently have a 75 gallon discus tank with abot a 3 inch mixed play sand eco flora mix for the plants . I keep my water at about 80 degrees and a ph of 6.8 to 7.1. I want to add some clams to the tank to keep the sand moved. I noticed the last group of clams moves under the sand quit a bit. Any thought or even other types of vertibartes would be helpful. Thanks

 

[midnight]

when yours died,did it pollute the water?
did ya have fish in with them?did they die?

im asking cus i have some clams.
i had them in a 5 gallon with some darter fish but i got worried and took them out.
the clams are in a 1 gallon tank now with just an airstone and sand.been for a few weeks.
that water hasnt been touched and is the clearest ive ever seen water.
might put them back in the 5 gall.

snails are good to move sand,i think the trumpet ones.
i caught some and they had babies so i been spreading them around to the other tanks.
they leave cool trails in the sand.