Brown SPS no PE, even at night

[DopeCantWin]

I got the coral brown and looking for some advice to get it back to normal. I'm using LEDs. Alk 7-8, Calcium 430ish, Mg a little high from getting rid of Bryopsis. Temp steady at 82. All the other SPS are growing pretty steadily, and coloring up. No AEFW or Red Bugs. Nitrates maybe around 5, Phosphates 0.

The frag that I'm having trouble with has been in the tank probably a little less than a month. I put it at the bottom to keep it from getting burned out by the LEDs. It's whitened out a little from lack of Phosphate, but otherwise stayed the same. I do feed my SPS Reef Chili.

Should I attempt to move it closer to the LEDs?

 

[ooja3k]

It may not have enough light that deep.

Move that sucker up and let him color up!

 

[rigleautomotive]

I got the coral brown and looking for some advice to get it back to normal. I'm using LEDs. Alk 7-8, Calcium 430ish, Mg a little high from getting rid of Bryopsis. Temp steady at 82. All the other SPS are growing pretty steadily, and coloring up. No AEFW or Red Bugs. Nitrates maybe around 5, Phosphates 0.

The frag that I'm having trouble with has been in the tank probably a little less than a month. I put it at the bottom to keep it from getting burned out by the LEDs. It's whitened out a little from lack of Phosphate, but otherwise stayed the same. I do feed my SPS Reef Chili.

Should I attempt to move it closer to the LEDs?

A stressed acropora will go brown and retract polyps for many reasons IME.If I use the info you provide as the only clues I have to base my assumption I would have to say zero PO4 is the cause.If you are measuring this parameter accurately and it is true zero then PE goes away and most of the coral or all of the coral will expel its colored pigments and start with a dirt brown color.
sometimes the base will go brown but the tips will remain colored.

I must say that excessive PO4 will look very similar at times and can easily be mistaken for the other without a accurate,repeatable form of measurement.I have studied the correlation of acropora color,PE and growth over a vast range of PO4 readings and I have found to my surprise that a given acropora will look almost identical when in poor health because of high or low PO4

That being said if you are at a higher then 1500ppm with Mg ,and the impurities that are added when used to battle algae,then this can also look veru much like the symptoms seen from elevated or depressed PO4.

Basically I am saying with what info you provided and the very general symptom or poor PE and brown pigment,there are many things it can be and I can theorize for days before helping you a bit.The deductive reasoning to know why this coral has stunted and is stressed is no exact science but as time goes on and your observations correlate with data you have from testing,you can be pretty certain you are going in the right direction to find the cure.

I would not target zero PO4 if you are measuring accurately as corals do not grow at this level.GFO or bac dosing should not oversee the fact that when PO4 is very low that this becomes your limiting factor and steps must be made to have some measurable PO4

 

[DopeCantWin]

I've measured PO4 using Salifert and Hanna, both read out as 0. I've always had 0 for some reason. I suspect it is Xenia. I'm also using Biopellets and Chaeto, but those haven't always been there and the PO4 has always been 0. I've added another fish, but the load is still relatively small. I guess I'll keep trimming back the Xenia, and see where I land. Another symptom that I see is acro bases which are relatively brown with little PE, but the tips have good PE, growth and color. I'm not using GFO or Carbon.

I've started to cut back on the Xenia, I'm hoping to get rid of most if not all of it. I can also feed some more Phosphaty food like flakes. In the meantime should i leave the Acro where it is, or move it on up?