So I'm about 4 months into using the ATI LED Powermodule and I feel I have seen some interesting results both positive and negative. Overall I feel the colors in my tank are outstanding, but I was struggling with getting reds and pinks to really pop, plus my stylophora that was directly under an LED cluster was "burning" on the top, and my strawberry shortcake was brown in one small area where it lay under an LED cluster, and I was having trouble with diatoms on my sand, and I felt my OT (Oregon Tort) was ever so slightly paler than I like. I therefore turned the LEDs off except for 1 hour in the morning and 1 hour in the evening. I had been running them 14 hours but only at 35% peak power. I didn't think they would have much effect at such low power.
It has now been a month without fulltime LED and I have noted several changes all for the better.
1) The brown area on the strawberry shortcake is almost all gone and the colony is regaining full color.
2) My purple humilis which was pale purple is turning radiant and deep purple.
3) My OT is regaining a deeper blue.
4) The pink birdsnest is turning to a glowing pink and a red coral that I have been growing from a tiny frag is suddenly changing from just dull brick red to a bright glowing red.
5) The top of the stylophora is healing.
6) A deep water suharsoi that was green is turning glowing white with radiant yellow tips.
7) A coral that was green with blue tips lost the blue tip but is now regaining the blue tips.
8) The diatoms on my sand are gone.
9) My purple efflo was dull purple and brown in the center and is now returning to all purple throughout.
Bottom line: 14 hours of LED light at 35% peak power was not good for some of my coral coloration. If I had to guess I would say that PWM (Pulse Width Modulation) is not as harmless as folks think. Although the LED looks dim to our eye the coral is feeling a firehose of photons that are turned on and off and this negatively impacts some zoox.
Not scientific at all just the observations of a long time aquarist, and before everyone gets all in a huff let me just add, I'm not putting anyone elses stuff down, I'm just making my observations and thoughts known to the forum AND I would note that Lunar (K. Tryc), arguably the greatest colorful coral grower of our day, had the exact same observation regarding the exact same fixture and even went so far as to remove the fixture and go back to a pure T5 setup. In other words please don't look at my comments as a put down. They are just one aquarists unscientific observation, so use that as any other piece of internet trivia with a proverbial "grain of salt".
Will try to get some photos later
