Why no Zoas or Clams?

[Gripenfelter]

Zoas and clams used to flourish in my tank.

I had an anemone explode in my tank back in August. Killed most of my coral including sponges, torch corals, hammerheads, toadstools, leathers, 3 clams, and other anemones.

Did massive water changes and ordered new coral.

Been a couple of months now. All the new coral is flourishing (same coral as above) but I can't seem to keep clams or Zoas in my tank. They die within a couple of weeks or close up all together.

What do you think it could be?

I do 10% weekly water changes.

Nitrates around 10 or less.

Ammonia is zero.

Nitrites are zero.