[Marcel]

What's the deal?

In my aquarium for the past 2 months all my sarcophyton, lobophytom and sinularia are closed up. Once in a while some of their polyps will expand only to close again the next day.

The funny thing is other corals do better than ever. These include Pulsing Xenia (forest), Nephthea, Open Brain, green star polyps, mushrooms, zoanthids and button polyps. All show excellent polyp extension.

I moved one of the sarcos and sinularias to another aquarium to see if they'll open up there. After 2 days they haven't yet. Older cuttings from the same corals that I put in the other tank a long time ago are doing fine.

Both aquariums use the same water source (RO). The problem aquarium had a bad algae outbreak a number of months ago and all corals were declining. Problem was phosphates, tied to a sandbed in refugium (it was just rotting). I removed sandbed, and used seachem's Phosguard to lower phosphate. Followed instructions. At the end (per instructions) I left one bag in tank for a number of days. Then, one night, power goes out during a lightning storm for couple of hours. Next day, these corals are closed up.

I saw on this site that Phosguard might affect leathers. Took it out. Have done a number of 20% water changes. But the condition doesn't seem to improve. After adding some iodine 2X I've noticed the polyps would open up on some for a day, but then close again.

As I said all other corals and inhabitants do excellent. I also added carbon, skim vigorously (Top Fathom 500), and currently running a polyfilter.

Any other suggestions?

Thanks for your time,

Marcel