Torch Coral Tentacles Shrinking

[Roy the Fish Man]

Hello. I have a 20 gallon cube mixed reef with LPS and soft corals. I am running an AI Prime HD at 50% overall intensity with blue, royal blue and violet at 100%. Red and Green are at 0% and Cool White is at 10%. The lights come on at 8 am and go off at 8 pm with a 2 hour ramp on each side (so 8 hours at full intensity). My torch coral's tentacles are fully extended until about 2 pm at which time they start to shrink. The next morning they are fully extended again. The flow is the same all day. The torch is about 2/3rds down from the top of the tank to the side. All my parameters are fine (Alk, calcium, Mag, nitrates, and phosphates). I change 1.5% of the water daily and dose 3ml of All for Reef daily. Any thoughts on what is happening to the torch (and how to fix it) are very much appreciated. Thanks!

 

[NAS]

Have you ever checked your lights with a par meter? Par may be too high.

 

[Roy the Fish Man]

I don't know the exact PAR so I will rent a PAR meter to check it. It just seemed odd that it would go all day until the middle of the afternoon and then start to shrink. Just curious, is there such a think as "accumulated PAR"? Kind of like us being in the hot sun all day and eventually getting tired? All the said, thanks for the input, I will definitely check it.

 

[NAS]

I don't know the exact PAR so I will rent a PAR meter to check it. It just seemed odd that it would go all day until the middle of the afternoon and then start to shrink. Just curious, is there such a think as "accumulated PAR"? Kind of like us being in the hot sun all day and eventually getting tired? All the said, thanks for the input, I will definitely check it.

I’m not sure honestly if that is something biologically/physiologically that happens to torches but it makes sense to me that it could. That’s what my thinking was when I suggested checking the PAR.

 

[chuck]

Maybe it's too much light maybe turn them down

 

[mumra]

I would try moving it first. You don't want to negativity effect the rest of your corals (assuming they are fine) by trying to please one. But be careful not to move it to far down. Light loss is exponential in water.

IDK, I've never had a torch but I think the philosophy of not changing something that could effect your entire tank just to help one coral is wise. .02