Well than that's not it lol

Try feeding some mussels and see if it take attn off of the clams. If it is a fish doing it

I find myself if I skip out on mussels my Cbb will eye up one of my clams

I saw you haven't changed any water in 6 months....

Ok so?

Why would they be closed?

not enough nutrients. thats why everyone says its still good to do WC to replace the elements

I don't know the science behind it but I've always changed my water, never had a problem with clams. The fact the issue is with more than one clam and nothing regarding lighting has recently changed it pretty much leaves water chemistry.

But I keep all my perameters in check and I have far more sensitive livestock that's doing just fine. I dose my tank daily

what are you dosing?

I think that clams are probably one of the most sensitive things that we can put in our tanks.....they are somewhat like a sea squirt.....they filter large amounts of water through themselves in a day....not as much as a sea squirt but still enough that the water quality needs to be excellent.......stability is key.....I dont recommend to any customer to put a clam in their tank until the tank is about a year old.....the first year of a tanks life is usually a very unstable environment.....the excitement of a new tank usually brings a lot of new additions, which in turn causes a perpetual teetering of the balance of the tank.....generally speaking the new additions tend to slow down after a year or so and the tank has a chance to catch up to all the "teetering" and mature......

But why all of the sudden? I've had them in there for so long. And I've seen noticeable growth.

I check my perameters with Hanna checkers. I'm certain that phosphates and nitrates are at 0

I dose kalk through top off and the separately dose calcium, alk, and mag when necessary