LED's and SPS loosing tissue

[drw94]

I have a question to see if there is a common thread between the two in my tank. Here is a little back ground. My tanks is a 60 cube with a total of about 50 gallons. I am running full zeo and following to a "T". I switched over to LED's about two months ago. I am running one AI Sol Blue. All corals where doing great initially with an explosion of growth that was unreal. Now that has settled down to a more realistic growth pattern. I have a montipora stellata that is losing tissue. It is not pests and I don't think it is RTN/STN. It is only losing tissue in areas that are not under the lights. The bottom sides of the whole colony has lost all the tissue. The areas exposed to the light have great PE, color, and still appear to be growing. Has any ever heard or experienced this before with their led's. All other corals look good. Parameters are stable and within recommendations for a zeo tank. Any ideas what is going on?

 

[mussel and hate]

Less reflected light to the underside perhaps?

 

[WingoLED]

I believe it has to do with LED being directional. I had the same experience when testing single 30W light source three years ago, I experience similar issue, from then on I spread the light source into 2 bars-one in front one close toward the back, the problem goes away.

So from then on I abandon the canon theory. However, I don't go spread the LEDs like 99% DIY build threads in here either. The even spread of of LEDs while incorporating lens at the same time create too much of a disco effect.

In the meantime, I like 2 3 bars arrangement but who knows 3 years later. hehe