Not enough light?

[StrangeDejavu]

So I came home with some frags last Saturday. Got everyone dipped and acclimated and they appear to be settling in. They are Lobophytum leather, Green Rhodactis, Acan, "Salmon Pink" Hammer and "ORA Green" zoanthids which I just assumed were Radioactive Dragon Eyes. My zoas were very intense looking at first, but have starting turning a brownish color. I'm running an AI Prime 8 inches above the water and 22 inches above the sandbed, 17000K set at 25% intensity. A little bit of digging around tells me zoas going brown means too much zooxanthelae, so does that mean I need more light over them? My Rhodactis also isn't looking as intense as it did the day I brought them home. The shop runs Radions over their tanks so i'm sure they were under much more intense light than my AI Prime could even put out at 100%. Here's some parameters and two photos. Parameters are a little outdated as my tank was 100% regular Instant Ocean salt at the time. I've since done a 25% WC with Reef Crystals and am working my way up to converting to RC completely.

SG 1.026
pH 8.0
Alk 10.8
Cal 345
Mag 1130
PO4 0.02
Nitrate 5
Temp 78

Here's how the coral looked last week. Both photos taken with the "All On" option in myAI, which is all colors at 100%.

And here they are now.

Here's a close up of the zoas from last week.

And the zoas today.

 

[Bl4ckDr4g0n]

My understanding is NO3 is too high, zooxenthelae algae will bloom heavy and brown out the coral. No expert here, yet to put coral in my tank but for growth I read you want between 1 to 2, and for color you want .25, calcium and magnesium seem low as well

 

[GimpyFin]

My first guess is that they are just not getting enough light. Especially considering they are at the bottom corner of the tank. You can also see in the second pic how they have started trying to extend toward the light more. I would try moving them up a little (Maybe on the rocks just to the left of the hammer in the second picture.)

 

[StrangeDejavu]

My understanding is NO3 is too high, zooxenthelae algae will bloom heavy and brown out the coral. No expert here, yet to put coral in my tank but for growth I read you want between 1 to 2, and for color you want .25, calcium and magnesium seem low as well

Yeah i'm working my way down there again. I used to consistently be between 0.25 - 1ppm nitrate but I recently had a month long battle with dinoflagellates. I went the blackout/biobomb route by dosing copepods, Microbacter7 and phyto heavily. All the phyto shot my NO3 up to about 7 and WCs are slowly bringing them back down. Ca, Alk and Mag should also be in good levels once my tank has fully switched over to Reef Crystals.

 

[StrangeDejavu]

My first guess is that they are just not getting enough light. Especially considering they are at the bottom corner of the tank. You can also see in the second pic how they have started trying to extend toward the light more. I would try moving them up a little (Maybe on the rocks just to the left of the hammer in the second picture.)

Mine as well. Looking at Prime PAR charts, the light peaks out at 250 PAR dead center 12 inches over open air. Most of my coral are 19 inches below the light, off center, at 25% intensity, receiving light through a glass lid and through water. If my math is right, that's about 20 - 30 PAR... I just bumped it up to 40% and will monitor closely.

 

[StrangeDejavu]

It was definitely a lighting issue. Lights have only been on an hour and a half at 40% and the zoas are already noticeably more green.