Thoughts on dimming lighting

[Ratpack]

I currently run two of the Reef Radiance DM155e's over my 75 gal tank. The lights are about 15 inches off the water in order to get a good spread of light. Everything seems fine and I am running them at 70% blue and 60% white and other colors. A lot of my SPS which are closest to the light seem a little pale and based on some others with similar lights, they are running at much lower intensity than I am. Do you think it would hurt the corals if I back down and kind of start over at a lower intensity and ramp up?

 

[Ratpack]

Actually just measured and they are 12 inches off the water and about 20 inches above the SPS corals.

 

[reefer gladness]

Without a PAR meter you're just guessing, metrics like how many inches off the water won't be particularly useful. If you can borrow or rent a PAR meter you can take real measurements around your tank.

Yes, starting off much lower and ramping up slowly is advisable. You may not even need to ramp up, the setting percentages are very arbitrary numbers. 30% on my LED units might produce PAR equivalent to a 70% setting on another LED unit as an example.

Remember, there's a lot involved in keeping SPS corals. The quantity of light may not be a factor in coloring at all.

 

[sirrealism]

Agreed ^^^^ SPS are drama queens and it could be anything that has them loosing color but I would start with a par meter. My reef club has a par meter so it makes the rounds for any one in the club who needs it. Are you involved with a reef club? Do they have one? They are not cheap but I think you can buy one for about 400$ What salt are you using? what are your parameters? Have you checked for iron,iodine,ECT? It doesnt take much to be off to make SPS unhappy. I for one can say that I switched from RSCP to reef crystals and my SPS are not happy about it.