Fauna marin Ultraclam and sponge power are 2 different thing. Sponge Power is made by zeovit and it's liquid and Fauna Marin Ultraclam is in powder.

I feed my clam DT live phytoplankton. Glad to known they can eat fish waste, as I had read they don't absorb anything else than phyto. That was for crocea clam.

I just lost my other 5 year old crocea today. It actually belonged to a friend for 1-2 years before I got it so I guess it was probably more like 7 years old. It didn't show any signs of a problem until last night when I saw it spawning. I've had clams spawn before and not die so I wasn't too concerned. Its been about 3 months since I've had a clam die... I only have two left now. A little 3"maxima and a 5" derasa.

Well, I'm back in town again (and by in town I mean one of my towns) and both of my remaining clams are open, and happy looking!! Whoohoo!!! I sure am glad that I didn't toss the Maxima before I went out of town last weekend. I was VERY close to doing it. So far so good.

Clam deaths seem to be something going on a lot this time of year. I have been hit myself with 2 clam deaths over the last two weeks. Neither of them have had pyramid snails and freshwater dips didn`t help.
It actually looked like something was deteriourating the clam from the foot up. There was no gaping or pinching in the mantle at all, until the day they died where the clam refused to even open and you could see there was something wrong with it.
I had checked all my parameters to see if there was anything in the tank and every thing came out normal.
ammon, nitrite, phosphates = 0
ph = 8.4
alk = 8dkh
salinity = 1.026
nitrates = .05

It sucks, so now I am watching my two remaining clams to see what happens with them.

Very strange. Next thing you know hundreds of birds will fall out of the sky and die... Oh wait... Nevermind...

Sorry I dont have time to read the full thread, however:

I have personally heard of (first hand, like from the one who lost them) 3 other instances of multiple clam loss in the last couple weeks, and seen a few go down in a store.

I wonder if city water parameters are connected? I know it caused multiple clam deaths simultaneously in two of the cases for sure.

Cheers,

Chris