LED??

[pjr]

What LEDs are you using?

[MizTanks]

Reef Radiance LumenTek Pro 180

[binford4000]

I also agree that getting the nitrifying cycle going is critical. I was looking at your bulb lay out. They sure put a lot of whites in the array. I also do not use the moon lights. I don't think there's any benifit in running them but for the reefers enjoyment. Total darkness is needed for coral to feed.if you look at your corals after they've been in the dark for a while you will see the feelers and polyps are out. We feed our tank 1/2 hour before lights out. The algae can be several things at one time. Nitrifying cycle,bio diversity,light cycle and or water quality. I would start with killing the moon light. Light is light and a blackout period will help slow algae growth. I would also increase my water change volume and use bio digest or micro bacteria 7 and feed the bacteria with a carbon source. Like vodka or my favorite bio fuel from britewellaquatic . How much coralline are you getting after the 19 weeks ? Coralline is a good indicator of the health of your water column

[MizTanks]

My tank is totally blacked out from 9pm to 9am. Lunars are for my enjoyment mainly, gives me a chance to watch my Conch cruze around
I agree with there being to many whites, but what can I do but keep them turned down? So far, I have 0 coralline growth I was thinking about this today actually. It is now 5 months old! I had big time coralline growth at this stage in my 26g.
@Tom -I did use 80# of live sand plus dosed an entire bottle of BioPronto Marine by TLF.
But this brown dusting crap on my SB has me stumped. It was getting better then about the same time I dosed Reef Roids it came back with a vengeance!

It costs me $10.00 a pound for LR at the LFS.