Zoas not opening. Stumped

[MichaelllHoh]

This is my first post on here and I was hoping I could get some help. I have had this tank for about a year and I have a variety of corals. Hammers, a torch, gsp, mushroom, Xenia, a sps coral, an anemone and another lps. And lastly zoas. Everything is doing great I’m seeing good growth great polyp extension and I like to think my tank is doing great. Except for my zoas they have never done well the whole time I’ve had the tank. I’ve moved them all over and they just stay closed. They even grow but slowly. I’m stumped on why I can’t keep beautiful zoas. I’ve dipped them looking for pests and no sign of any and checked at night.
Any suggestions?

I have them in low flow and low light currently next to my mushroom.

alk 8
Calcium 460
Magnesium 1400
Phosphate.05 gfo reactor to keep at this level
Nitrate usually 0 recently tested .25 ppm
Salinity 1.024-1.025
Temp 79 degrees

 

[Dom]

This is why I’m stumped. They are considered one of the easiest corals. But the worst in my tank. When more “difficult” corals are thriving. Very odd. I do monthly water changes. And I dose brs 2 part to stay stable. I suppose I could try more water changes but I’m not sure why it would be necessary if my parameters are stable. I’m not trying to over complicate. I’m trying to understand. If more water changes are the answer do you suppose it’s trace elements?

Good that you are trying to understand. I'm not the guy to ask about trace elements as I continue to learn about water chemistry myself.

The reason I recommended water changes is because salt mixes are "supposed" to create balanced water chemistry in which all corals are supposed to find the elements they need to thrive.

So for me, I sustain proper levels by keeping my water changes consistent. This has worked for me, although, some of my corals in one of my tanks have become so large that I am beginning to supplement as ALK and Calcium demand exceeds what can be provided during weekly water changes.

I'm curious; do you have a cleanup crew? Perhaps you have crabs and snails walking on them and causing them to stay closed?