I have a small dersa clam that I have had for awhile.
His mantle has receded about 1/8in to 1/4in into the shell. This is the same clam that had a hole in it but has healed.

The parameters on the tank is normal and the other larger gigas clam is doing perfect.

How often do you do a freshwater dip to help them get back to normal??
I did one today for 25min and hes back in the tank looking a little better.

Thanks
Dan