4.5 month update; a month and a half ago, I started noticing some color loss on several sps. High lights, high alk and ultra low nutrients were the most likely culprits. So I cut the radions from 85% to 55%, and switched out the 80deg lenses to 120 wide angles lenses; cut alk from 11 to 8.5 dkh, added several fish + cuc and started feeding corals. I also STOPPED water changes to build up nutrients. Today my parameters are: alk 8.9 ca 435, mg 1360, nitrates 1 ppm, phosphates 0 (Hanna phosphorus ULR). Ph 8.2, 78f, 35 Sal. Fish are fat, Noticing improvement in color in the few frags that were growing pale but overall color is not great. I decided to get a par meter to help me tune my Radion xr15s gen3 pros. Went for the Seneye reef monitor based on BRS's review.
I did this map of par on my corals; radions were at 55% 18.5k (Ecotech's sps a/b+ program).
Ecotech's coral lab experiment, suggests to have sps between 300 to 200 par. My values were all lower than that. I was worried that the Seneye was underestimating par, but this par simulator for the radions suggested otherwise
http://www.aquaticlog.com/radion
Briefly, you setup your program and light specs and the algorithm with let you visualize par at different depths and horizontal distances from the center of the Radion. The Seneye was actually bang on given the position of the corals relative to the light. I think the combination of the Seneye and the light simulator will be very helpful in figuring out how to tune the lights to get my sps in the 200 to 300 par range. For example; looking over the top left sps shelf; I can get these frags to 200-300 par if I up the intensity from 55% to about 80%. (Over a few month of course)
I had fun going from frag to frag and simulating how changes in light intensity would influence par. I quickly realized that I made some aquascaping / coral placement errors. The radions, even with the wide angle lenses, have hotspots right under the lights. I had placed a few acropora's on a 12" deep shelf that is now getting about 110 par. Most of my other acros are 6 to 8 inches deep. Using the simulator, I couldn't find a sweet spot intensity that would get the bottom right shelf to 200-300 par without potentially scorching the frags on the top shelf. My mistake was I should've designed my sps shelves to be mostly at the same depth to avoid overexposing or under exposing shallower or deeper frags.
So now I have a dilemma... do I raise up the bottom right shelf by 3 to 5 inches? (Easiest), lower all the top shelfs l by 3 to 5" (lots of work but possible) or simply keep it where it is. The deep sticks are still growing and they will get more light/ par as they grow up?...
What do you folks think?
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