Plate coral unhappy.

Gjedde · Mar 25, 2026

Everything in my tank seems to be doing very well other than plate corals. I traded my nice plate coral away a couple weeks ago, lost another plate a couple months ago, and my last plate is looking like this now.

Tank is a mixed reef 150 gallon. Nitrates are low at .2 phosphate is around 10. Typically stays in that range. Getting great growth out of my acros, ive got pectinias, favias, chalices etc that are growing great. My frogspawn, torch, and octo spawn are all very happy.
The only other coral that doesnt loom great is one of my hammers, just not super extended or puffy.
Lighting is 5 noops and t5 hybrid. Noops are at about 60% and the t5s are on for about 5 hours a day.

Any thoughts on why i am having such trouble with plates?

Gumbies R Us · Mar 25, 2026

@VintageReefer

Gjedde · Mar 25, 2026

Corals placement in tank. Ill try to link a recent icp as well ince i can get my kids down for a nap.

kevgib67 · Mar 25, 2026

@kingranch2003 ?

kingranch2003 · Mar 25, 2026

Does it appear to inflate itself and try to move under that rock shelf, or did you place it there. The plates will try to move to the conditions it likes best. If it's trying to get in a shadow, you may have it in too much par or flow.

Gjedde · Mar 25, 2026

I put it there. It hadnt moved from its position for a month. I may just experiment with location.

JumboShrimp · Mar 25, 2026

IMO, Plates are challenging/tricky. Hats-off to anyone who can keep them healthy, long-term. Wishing you the best.

jp_75 · Mar 25, 2026

Honestly i don’t think i know anyone who keeps them long term
Very challenging coral.

kingranch2003 · Mar 26, 2026

JumboShrimp said:
IMO, Plates are challenging/tricky. Hats-off to anyone who can keep them healthy, long-term. Wishing you the best.

They certainly are odd little characters!

They're so intresting, but definitely a unique experience with almost each and every one as its own personality.

Gjedde · Mar 26, 2026

kingranch2003 said:
They certainly are odd little characters!

They're so intresting, but definitely a unique experience with almost each and every one as its own personality.

Thats what mine used to look like. Had it for about a year before it started getting grumpy.

Gjedde · Mar 26, 2026

Recent icp.
I am going to experiment with flow. I previously had one dmp40 on each side of my return(penninsula), i added both of them to one side of the overflow and noticed that the flow for the sps is as good if not better and the the flow for the plate seems to be better.
How often would you move the plate around to find a better spot? Not sure how long it would take to show improvement.

JumboShrimp · Mar 26, 2026

I bet LFS's do sell a lot of them-- they have a 'look' that makes you just want to bring one home to the tank.

Gjedde · Mar 26, 2026

My best lfs(empire corals in spokane wa, amazing prices btw) has lots of them and his guess was too low of nutrients which would make sense. Maybe the solution is too low of nutrients, more fish!

kingranch2003 · Mar 26, 2026

Gjedde said:
Recent icp.
I am going to experiment with flow. I previously had one dmp40 on each side of my return(penninsula), i added both of them to one side of the overflow and noticed that the flow for the sps is as good if not better and the the flow for the plate seems to be better.
How often would you move the plate around to find a better spot? Not sure how long it would take to show improvement.

Ill say that every single plate that I've ever had, has gone through periods where it looked like this. Maybe it's a week, maybe it's a day, they usually bounce back. It's an alarming look when a fungia retracts like that, because it looks like recession. They
fact is, these corals have a unique ability to retract and inflatemore than your typical coral.

My orange plate (Sweetlips) was so retracted for 2 weeks that I almost pulled her out of the tank, then one day she did this.