Ok I have asked a few questions on this thread. U r all very helpfull thx.
I have and ati 8x54 over a 120 frag tank. Currently running 5 blue plus 2 coral plus 1 purple plus.
The sps are loving it color and growth is great. The zoa ans paly are also loving it for growth and even seem to have good color but they don't open fully anymore. To much light is my guess. I do also have 2 30w led strips on this tank.
Some corals are very sensitive to red light. Some varieties of zoos and Acans are in this group dependent upon there protein pigments. Excessive red light will cause them to either close down or not open fully to protect themselves from they are suspecting is excessive light. This is noe of many cases where to much light is just as much of an issue as insufficient light.
The issue could be corrected by either swapping out the Purple plus for another Coral Plus for a minor reduction in the red spectrum. You cul;d also replace it with a Blue plus for a little more drastic reduction in the red spectrum. Another method would be swapping out one of the coral plus bulbs for another blue plus. But be aware that any of these changes will also change the over color look of your tank.
I am running the 2 led strips for 12 hours, 2 blue plus bulbs for 11 hours, the 6 remaining bulbs for 4 1/2 hours.
I have been thinking about different things to lower the intensity. Maybe turn down the duration on the 2 blue plus bulbs to 8 hours and the LEDs down to 10 hours?
Or
Add 2 actinic bulbs to the 2 bulb slot?
Or turn off the 2 bulb slot all together since I have the 2 led strips?
Raising the light any higher is not an option
Any suggestions?
First off running a 8 bulb ATI fixture on a 120 gallon tank will bring your par numbers to close to the max for virtually even the most light demanding corals out there. Now your also boosting that with LED's. So my first uestion would be for details on your two LED strips. they could be almost as powerful as your T-5's or as weak as not being an issue dependt on what they are on how they set up?
Note I'm usning 8 T-5's over a 120 with LED's but my fixture is a modified hybrid and not quite as powerful as the ATI fixture. Yet I had to move some corals mainly Zoos into shaded areas. For some reason green Zoos grow like wild for me, but those with a lot of red of red in them will only grow in more shaded areas.
Also to give you an idea of my timing right now,
LED strips all blue light = 11:00 AM to 12":00 PM 13 hours.
2 ATI Blue Plus bulbs = 1:00 PM to to 11:00 PM 9 hours.
6 ATI bulbs, 1 GE 6,500K, 2 Purple Plus, 3 Blue Plus 3:00 PM to 9:00 PM 6 hours.
Every couple weeks I'll switch the midday lights off for a couple days to reduce the light occasionally.
I even thought of adding a shade rack on top of the zoa and paly frag rack?
I know I'm all over the place just brain storming.
Thx
Roger
Thje shade rack is a touchy situation. Excessive shade could hurt you as well. Any chance of moving the Zoos to lower point in the tank? Aslo if the reduction in the red light is not helping you can try some atinics in place of the vlue plus but try them one at a time. The difference between a Blue Plus and an atinic is usually greater than most people think it is.