PO4 or LED 10K Lighting question

[dwing27]

So here is the details. You vote. I have a 57 gallon rimless. 2 yrs old. I test my water 2-3 times per week and input the data in an excel spreadsheet. Parameters - ALk - 9; Cal - 420; Mg - 1320; PH - 8.2; Salinity - 1.026; Nitrate - 0. At least 6-8 months worth of stable data. Heres the problem. I have never had success with SPS. I am doing one last trial before making a change. I have recently added a green monti, red monti and green slimer. Traditionally easy SPS corals. Within the first month, the Red Monti has gone from bright red to a pale pink. The green monti is starting to slowly fade and the green slimer looks great but hasn't budged. So here is the question.. Phosphate testing is done via Hanna Colorimeter. I average between 0.00 - .06 depending on the test. Hanna checker isn't always the same even on multiple tests but I have never had higher than .06. Lights - I have (2) Kessil A150w 10K pendants about 2 years old now. I recently read an article that stated 10K spectrum lights have more red light which inhibits SPS color and growth. So would the most likely cause of my slow demise with SPS the lights (lack of blue spectrum) or the slightly higher then .03 PO4 on occasion?? I am taking pictures throughout this final test phase. if this continues I will try T5 since it is tried and true. Hopefully this process of elimination will finally lead me to an answer.

 

[jackson6745]

Get yourself some nitrate and you'll see better colors. I've seen plenty nice SPS tanks under Kessels, non of them are traditional low nutrient. Getting higer no3 can be tricky. Some guys dose sodium nitrate, I prefer to add more fish while using bacteria, carbon source, and or GFO to keep po4 relatively low in comparison. Acropower might be beneficial to you as well

 

[dwing27]

Yeah I only have 6 small fish and have had the same bioload for the past year. I do use GFO for PO4 removal. I have been trying to eliminate possible reasons for the past few months. I didn't think I was running a ULNS. I haven't been direct feeding corals because I was thinking high PO4 was the culprit. My only reason for wanting to try something different is that I have had the tank stable for more than a year and have tried at least 10 different species of SPS and they have all slowly faded and died. I also have not had any growth in any coral (Zoas and LPS). I have nuclear green paly's that look the same today as when I bought them more than a year ago. My two acan colonies have been healthy looking for more than a year and have not split. Very frustrating. I guess it is possible that in my quest to provide the cleanest environment I am actually not providing enough nutrition to the corals.

 

[Reefing Madness]

I'd be looking into different lighting, statistically speaking SPS best growth are at 14k range, not at 10k. Also, I'd think about a higher wattage also, getting away from the 150, but if you like that unit I"d go with the A350W.