changing lighting percentages when corals are thriving

[MichaelClark55]

I have a 125g mixed reef tank with a lot of corals. About half are mother colonies. I have a 32" SB Reef pro timer hanging in the middle flanked by a Mars Aqua 16" on each side of the SBR. They are 14" above water level. I have had this setup running for just over a year. The Mars are set at 80% white and 20% blue. The SBR light is set at 80% blue. My question is it going to mess up the corals if I turn on some white on the SBR light? If I need to stay at the same intensity should I turn the blues down to 60% and add 20% white? (lowest white setting) or would be ok to stay at 80% blue and add the 20% white? Do I need to run a PAR before considering this?

 

[Ron Reefman]

Knowing where you are in terms of PAR is always a good thing, especially with leds.

IMHO adding 20% white will only bump the PAR up a small amount. Especially if you do it 5% or 10% every week or two. Just remember that your coral's zooxanthellae do much better photosynthesis with blue spectrum than with white.

 

[MichaelClark55]

Knowing where you are in terms of PAR is always a good thing, especially with leds.

IMHO adding 20% white will only bump the PAR up a small amount. Especially if you do it 5% or 10% every week or two. Just remember that your coral's zooxanthellae do much better photosynthesis with blue spectrum than with white.

I agree totally with what you are saying. The white is really for my viewing. The Mars sections of the tank display better. The problem with the SBR light is 20% is the smallest increment in adjustability. I may reach out to Mike and see how I can adjust smaller increments. Thanks for the advice Ron.

 

[Ron Reefman]

You could go ahead and do the 20% bump. But cover half or 3/4ths of the white leds. Then uncover some every week or two.

Before I had a 6 channel fixture I covered the reds and greens to do away with the disco effect.

 

[jda]

Go slow, wait a while for a response. It is OK to wait for longer periods of time just to be safe... like bump 5% and wait a week.

There is more to coral than just photosynthesis, but there are zoox and proteins that work from 350 to 850nm, so white light does help with photosynthesis too. It can also color corals better to most eyes. Most "whiter" tanks still have massive amounts of blue, so it is not like anybody is forsaking the color range. Generally speaking, daylight to render and grow and then "blue it up" for your viewing pleasure - there are more colors to pop at night under blues if you have some daylight running.

 

[MichaelClark55]

You could go ahead and do the 20% bump. But cover half or 3/4ths of the white leds. Then uncover some every week or two.

Before I had a 6 channel fixture I covered the reds and greens to do away with the disco effect.

Great idea thanks!

 

[MichaelClark55]

Go slow, wait a while for a response. It is OK to wait for longer periods of time just to be safe... like bump 5% and wait a week.

There is more to coral than just photosynthesis, but there are zoox and proteins that work from 350 to 850nm, so white light does help with photosynthesis too. It can also color corals better to most eyes. Most "whiter" tanks still have massive amounts of blue, so it is not like anybody is forsaking the color range. Generally speaking, daylight to render and grow and then "blue it up" for your viewing pleasure - there are more colors to pop at night under blues if you have some daylight running.

Good points, well taken. I will do just that.