Help! Zoas not opening and getting worse

[gibbs.david]

Until 10 days ago my tank was flourishing but then Zoas started to close up for no apparent reason. The only noticeable thing was it started with one colony and almost like a line through it. I had been struggling with a dosing regime as I switched test kits from Salifert to RedSea with the latter giving higher figures.

Ni 0.5
Cal 415 (Salifert) 437 (Hanna)
Mg 1300 (Salifert) 1350 (Red Sea)
Kh 9.9
Salinity 1025
Temp 80

I just cannot understand or explain why they are struggling as I have the opposite with Duncan’s and Hammer Coral. Any help or guidance would be appreciated before I lose colonies.

 

[SashimiTurtle]

Tagging along, learning zoas myself and I have a few new frags that aren't opening all the way.

One thing I see is I think "Ni" is Nitrate? 0.5 seems a bit low for zoas?

 

[Crreef]

Check how much flow they have. One of my colonies started turning brown because they didn’t have any flow. After about a day from giving them flow they were back to normal.

 

[DSC reef]

I've had this phenomenon happen with blue hornets a few times to the same colony in the past 5 years. I can't explain it. I dip the zoas in coral rx then most of them loose the ring in the center then after 2 weeks look amazing and grow for another year. I do loose a few with a "valley" going right through the colony. Never see any pests come off in the dip. Very strange.

 

[gibbs.david]

Dipped yesterday and some some pests but not Nudibranches (at least I don’t think they were). Let’s see if there’s a recovery?

 

[jantje]

zoa need fot sure some Nitrate.
If you have no algea in your tank, and a true low 0.5 ppm nitrate it could be good for them to rais it a little

 

[gibbs.david]

Sorry, my nitrate is 5. Error on my part.