Frustration
Well - here is my update.
About 10 days or so ago, I decided to put the larger crocea back into the tank. It was looking good in QT....but the washing out of color had me concerned. I was also curious as to what would happen if placed back into the tank after 21/2 weeks (I think that's how long it was treated)...I'll have to look back at the thread. A few concerns I had were: 1. if the tank had protozoans....is it free of them 2. the smaller crocea was still symptomatic in QT. Is it possible with a tank full of metronidazole that the protozoan would be able to travel to the larger clam not showing any symptoms? 3. would the larger crocea still have an infection even though it looks fine.
Well, the coloration returned quickly after being removed from the metronidazole treatment and getting back to its spot in the tank. It did look like it pinched up a bit (this clam never really pinched as much as curled), but I attributed this to the flow in my tank. A few days after being back in the tank, I noticed the slime coming again. A week later I thought the clam might actually be fine....except the slime. This morning the clam looked great (minus the sliming).....I checked the clam in QT, and it looks good, too. The QT had a 100% water change....I ran out of metronidazole about 4 days ago. I began to consider moving the clam back to the main tank.....it isn't curled or pinched, but still had some slime. When I checked the main tank a little bit ago, the larger crocea is showing a tiny bit of curling. The thing that sucks....my metronidazole still isn't here. I tossed around doing the hyposalinity treatment like Maxx, but I want to see if it will work first. The hyposalinity idea came about from earlier in the thread....Illusion posted about his PM going away after his tank dropped in salinity for a week. When this thread first started, I didn't have lighting/MH set-up where I would feel comfortable having the clams QT for a week. Now that I do, I may give it a go.
What is the most frustrating to me of this whole thing....I don't feel like I will be able to keep clams because as long as I have these 2 croceas, I could spread it to other clams. Also, if these clams don't make it....I don't know that I would spend the money on a new clam to see if the protozoan is still present in the tank.
Another question I have, is whether or not the protozoan can become resistant to the metronidazole treatment.