Nutrient levels and light intensity

[spkennyva]

Are there some general guidelines for adjusting light intensity levels as the nutrients increase? My current belief is to increase intensity as nutrients increase, but just don't want to make a mistake. I've fried corals before with my lights. My 40B is 3 years old and is currently growing a variety of SPS, but for the last year my NO3 and PO3 have been basically 0. Following the general consensus here, I've been attempting to increase my nutrient levels. I'm doing this by feeding much more, and dosing KNO3. For the first time in over a year, the Salifert test is showing some color. Still less than 1 ppm, but things are moving. I'm going slowing with all adjustments. The corals seem to be responding well to the increase in nutrients, but some that were pale have now started to go towards brown, with the color more at the tips. I still have some pale corals, with others moving towards brown. Growth has seemed to also improve. My lights are a hybrid LED/T5 combo. I have two 165W Chinese LED fixtures about 8 inches off the water. This is augmented by 2 T5 bulbs (B+ and C+). The LEDs are set to 50% intensity on the blue channel and about 10% on the white (white/red/green). My experience with the white channel is that the corals are very sensitive to increases and can easily get burned, so I'm somewhat reluctant to increase it.

Current light schedule:
LED blues 13 hours
LED whites 2 hours
T5 (B+ C+) 5 hours

Any pointers?

 

[scar79]

I think you're on the right track - just go slow. If you have a well documented coral like Red Planet for example, you can get a gauge on your light levels before you go burning stuff with too much intensity.

I have a Red Planet colony that was somewhere between pale and brown before I started regularly dosing KNO3 and has now developed a really rich green base. Since I know that it will lose the green base and develop brighter pinks over a white base under high light, I will be using it as an indicator of my overall intensity as I continue to build up. This, of course, will be a slow process. I would wait at least 3 weeks between adjustments.

Best of luck, take it slow!