Orange Lobo & purple plate corals receding

[MarlinHooker]

In addition to my green polyp toadstool I have an orange lobo & purple plate which have started to recede. they are both sitting on the bottom of the sandbed in areas of moderate flow. My lights are 2 AI white Sols set at 65% max during the day + 6 blue Powerbrite strips and 2 Actinic blue + T5 48" bulbs. Other critters in my tank include a rose bubble tip, large frog spawn, med hammer, 3 different trumpets, several monti cap frags, 1 sm digi cap, couple of chalice frags & acan frags & 9 small fish. Tank is a 150g with 48"x 20" sump & 20"x18" fuge. I run GFO, carbon & a UV as well. There is 1 MP40 set at 60% and a 2nd was added last night both running the Ecosmart NTM as master/slave.

Temp is 79 deg run with a chiller, Ph hovers around 8.0, Phospate is 0.1, Nitrate is 1.5, Ammonia 0, Alk is 7.8, Mg is 1150 Ca is 380. I have begun to dose Mg & Ca within the last week as I just got my Mg kit & discovered that my Ca colorimeter from Hanna is not reading correctly (it was showing 500). I also do a weekly PWC of 15 gals.

Everything else mentioned above are all doing fine with no stress signs and several showing signs of sm growth.

So, is this a water movement, light or water chemistry issue or some of all 3 or something else? And, what should I be doing to turn it around? Thx!

 

[Reef Bass]

In my experience, chronically low calcium and magnesium can have that effect. Even if those aren't the cause here, I'd recommend bringing them up to more midrange values. I'd also try feeding if you haven't already. Again in my experience, supplemental protein can help turn recession around if the animal is still interested in eating.

 

[MarlinHooker]

Ok thx, Mg is now up to 1260 and Ca is 400. For target feelings should I do that at night? The plate coral at least puffs up once the lights go out ...

 

[MarlinHooker]

I plan to keep Mg at around 1280 and Ca at 420 ...

 

[greech]

Feeding at night is usually easier because corals are typically already in "feed mode". However, if you reduce or turn off the flow and squirt some meaty foods on them, they should respond. Those numbers look good but I seem to have the best success when Mg is 1300+. With that size tank and so few corals to consume elements, I am a little surprised you are needing to dose at this point. What is your specific gravity and how are you measuring it?

Lighting could be an issue. What is the height of your tank?

 

[MarlinHooker]

I can bump up the Mg ... SG is 1.025 measured with a MA877 Digital Refractometer by Milwaukee Instruments. The tank is 24" deep. Too much or too little light?

 

[MarlinHooker]

so is there any value in doing a Coral Rx dip for each of them?

 

[greech]

With tissue recission, too much light would be the issue (IME). I don't think your lighting is too much for these corals under healthy conditions or once they are acclimated to your lighting. I didn't see where you mentioned how long you have had these corals but at 24" you do have a fair amount of light. If they came from a lower light setting at your LFS then it may have been too much too quick.

Not sure about Coral Rx but an iodine based dip (Lugols) wouldn't hurt.

 

[MarlinHooker]

They actually came from another reefer in my local club from an established 180. I've had them for about 3 was. Right now they are in the middle of the tank on the sanded so are you suggesting I move them more toward the sides where they would not be receiving direct light? Given that I only have 2 AI Sols the edges of my tank don't get the same intensity as the middle

 

[greech]

If you feel that your lighting is stronger in comparison to their previous system then yes it wouldn't hurt. I'm betting the Mg being bumped up will help out the most but the lower lighting is a good precaution.

 

[MarlinHooker]

It's hard to tell since he didn't have AI Sol LEDs but il move them a little out of the direct lighting but I would think the water parameters would be the big thing as well, thanks