lighting question

[gjuarez]

Changing the color could have a negative or a positive impact. If the coral is not used to being blasted by high amounts of light it could bleach a little, but there is also a possibility that it could get better coloration. Like mentioned before, the amount of light is not the important thing when it comes to coloration. You can put a 400w 6.5k Iwasaki bulb and it will grow like crazy because they are super intense, but it will do hardly anything for the color. Gary gave us an example of a frag he gave to Texas Todd. Todd has an awesome lighting setup and he is using a combination of different bulbs, some of which include the reeflux bulbs. Reeflux bulbs peak at around 470nm and thats why it reflects nice colors of his corals. In addition, if I am not mistaken, Todd also has VHO actinic supplumentation that provides the 420nm that Gary was talking. 420nm not only reflects nicely of the corals but it also helps create the pigmentation in the zooxanthellae algaes. What type of 10k bulbs are you using?

[ou812pezz]

Coralife HQI Double Ended Metal Halides and Coralife Compact Fluorescent actinics. I can say that corals look bright during the actinic cycles(dawn and dusk) but are even brighter under the blue moon light. I think I should be patient for now. thanks everyone.

[gjuarez]

Yeah be patient, I have a couple of corals in my tank that have the most amazing color and then I have one frag that just browned out for no particular reason. Sometimes I guess it just happens. I am sure they will get their colors back in no time.

[GaryP]

I've had corals bleach out and I almost lost some when I went from an old higher K, lower PAR value bulb (Blueline 14K) to a lower K, higher PAR value bulb (XM 10K). My birdsnest was almost gone as a result. Sudden increases in light, even from replacing with new bulbs can have an impact. I noticed that Sanjay rotates replacement of his bulbs in his system. Of course he has something like 4 bulbs on his tank and replaces one every 6 months. But this practice would seem to even out the average light in the tank rather then getting a sudden increase every time you replace bulbs.

I learned my lesson and whenever I replace bulbs I cut back the timers and slowly increase the time they are turned on to help minimize the light shock the corals get. Other impacts can occur as well. More light = more growth = more demand for calcium and alkalinity. I watch my levels more closely after a bulb change to make sure my dosing keeps up with demand.