Pinched mantle & freshwater dip

[Doug]

Has anyone given there clam a freshwater bath. Its suggested for 20min. or so. Seems to be the only solution to a pinched mantle but it gives me the willies.

One of my derasa clams, which are usually not inclined towards this disease, seems to have just developed it out of the blue. How the heck does that happen? Sheez? I cant see taking a nicely growing derasa and plunging it into freshwater but would hate to see it spread, if thats what it is, to my other clams. I already noticed a very small amount of mantle, turned at the back of my larger derasa now. My crocea seems fine so far.

I had a maxima, that I got from another aquarist. Not sure if you remember the pics, but I say it had the disease from the start, when he purchased it. Now the others were not in the tank at the time, and were added right after it died, but I wonder if it can carry over in a tank with no clams for a few days?