well, the reason I say this is because:
1: in my 20g brackish tank, I have pool filter sand, so I know the behnefts of sand, etc
2: yesterday I put my pair of firemouths in the 75g with the silica sandblasting sand and they immediately sunk to the bottom as if they were sick...then I watched one of them closer and it started to turn on it's side like it was laying down, so I immediately rescued them and put them in a different tank where they are doing fine now
I was just wondering if it is possible for the sand to poison them or something
I know nothing of my water parameters, I am getting a test done today