Tone:
I did twice the increased magnesium treatment, first time with Seachem product (Mg sulphate), then with Kent Tech-I, as recommended. This almost killed my pavona, green and beige porites on Christmas tree rocks, but bryopsis returns always. I used RC thread about it, but result was different.
joker577:
It was sold as baby Tridacna maxima, here is how it's mantle looks:
and the shell at beginning:
burning2nd:
Thanks, will continue to do that. Yesterday tried ChemiClean to oxidize the organics, settled on tank's surfaces, including shells. So far not much difference. Tried also Red Sea ProtoBac, didn't helped.
maxx:
I bought them as Baby T. Maximas, 3/4" in size:
The attached themselves to the rock, and one moved around, until settled near the second. They grow, and after an year they were too close to each other. Had to cut off both and place them on halves of shells, like Clams Direct forum described. The are still attached to the half-shells, and I'm not happy about it: the microfood settles there and bristle worms found their way even there.
It's a small tank, 20g long, the urchin may damage or displace the Christmas tree rocks.
I was hoping on more radical solution, except for making personal clean tank for clams.
I know, that they will grow big. If they overgrow the tank width, I'll try to give them to somebody else.
Thank you all for the help and info!