Please diagnose my Tridacna！

94Rudolph · Jul 24, 2022

which suddenly shrinks today, and the other two seem normal，

I have been raising them for more than three years, in the last two days, a fish died in the rock crevasse, I can not take it out, about 5cm, 140L of water in my fish tank, Berlin system for 5 years, coral are all normal, could it be bacterial infection? Or fish infestation? Snail ingestion has been ruled out

94Rudolph · Jul 24, 2022

Oh by the way, I just tried adding two drops of Zeo Sponge Power，This is what it looked like half a month ago

minus9 · Jul 30, 2022

It's hard to tell from the pictures, but it doesn't look like there's much new shell growth? Is there a nice margin of white shell growth at the margins of the shell?

94Rudolph · Jul 31, 2022

Yes, I'm sure it's growing. I took it out to clean the shell and soak it in fresh water, it seems to be recovering now. Although it doesn't look like the tissue is shrinking

minus9 said:
It's hard to tell from the pictures, but it doesn't look like there's much new shell growth? Is there a nice margin of white shell growth at the margins of the shell?

minus9 · Jul 31, 2022

94Rudolph said:
Yes, I'm sure it's growing. I took it out to clean the shell and soak it in fresh water, it seems to be recovering now. Although it doesn't look like the tissue is shrinking

As long as you can see new white shell growth on the top margin of the shell, it’s growing. You can’t tell growth from the size of the mantle, the shell is the easiest way to tell. This is easily seen at night when the mantle is retracted.

94Rudolph · Aug 1, 2022

minus9 said:
As long as you can see new white shell growth on the top margin of the shell, it’s growing. You can’t tell growth from the size of the mantle, the shell is the easiest way to tell. This is easily seen at night when the mantle is retracted.

Thank you very much for your help. They look great now.Fascinating patterns and colors！