Lighting math.

[adonis311]

My current lighting is 2x 96w actinic blues for probably 10 hours, then switches to 2x metal halides for 6 hours. I was thinking, would that be considered excessive lighting? I'm having a constant issue with brown and hair alge and I originally thought it might be nitrate or phosphate caused, but even the lab testing confirms that I only have trace elements of both in my tank. Would going down to 65 watts in my actinics hurt anything?

 

[eric b 125]

What do you have in the tank? Your nitrate and phosphate may be giving a low reading because they are being consumed by the algae. How old are the bulbs? How often do you feed?
My T5's are on for 15 hours a day and my MH are on for 7 hours. Maybe you ought to cut back on the MH and see where that gets you. Without knowing what is in your tank it's difficult to say.

 

[smallreef]

I agree with Eric... Id cut down both though,,, say 8 hour daylight total...The lighting is feeding into the algae but any nitrate and phos are being eaten up by it to so your levels are going to show low...
another factor is feeding... could you possibly be overfeeding???
assuming you have a sump what i would do is put some macro algae in there with a light on an opposite day schedule than the DT, after pulling and sucking as much algae out of your DT as possible

 

[adonis311]

Livestock in the tank is 2 true perculas, 4 chromis, target mandarin, gramma, and a pink bar goby. The tank is 6months old, 75 gal with 107 lbs of live rock. There is no sump yet but I am using a converted canister filter as a refugium for macro and Copepods in addition to a protein skimmer and a bio wheel filter. Corals are 3 mushrooms, 3 colts, 1 zoa and 2 polyps. Plus crabs and snails.
Feeding is one cube frozen directly fed to corals every other day.

 

[smallreef]

your feed a whole cube to your corals? Im assuming the fish eat off of that too?
are you rinsing it before you put it in your tank? getting all the liquid stuff off of it so theres no cloud of misc stuff when you feed?
I have a feeling you arent and that is causing alot of phosphates in your tank...

 

[adonis311]

Your feeling is correct. I never thought of that but I will definately be doing that from now on. Should I still reduce my actinics to 65 watt?

 

[smallreef]

No your actinics don't make a huge difference when it comes to algae as far as I know...but until you get it under control you may want to just cut down your total light cycle for a few weeks...

 

[adonis311]

Got it. Just the six hour light cycle is enough then? Do actinics need to be replaced every so often like M. Halides do?

 

[smallreef]

Yeah they do...are they T5's? I think someone said those bulbs last for 12 -16 months?