Light Schedule/Settings

[ReefToad]

Hello all,
I've been dealing with an algae issue recently and I've come to the conclusion it has to be my lights. I'd like to point out this is my first reef tank so my experience is moderate. I use the Cetus 2ss and have it on the preset schedule, supposedly simulating the great barrier reef. However, the lights are on for nearly 18 hours a day which seems to be way too much according to practally everyone. I have a 15 gallon mixed reef with hammers, acans, xenia, duncans, discoma, walking dendro and some encrusting montis. The montis have begun to brown in color, but water parameters are all good. How many hours should I have my lights on? What brightness? Percentage for blues and greens/reds? Any insite is appreciated.

 

[Mr. Mojo Rising]

IMO they should be at the correct par level for 8-10 hours.

I would not blame lights for algae, we all use lights in this hobby but we don't all have algae problems.

Corals browning out is usually due to lower light levels or increased nutrients. Since you have algae, I am also leaning towards increased nutrients. What are the nitrate and phosphate levels?

Do you have enough water movement in the tank? Algae likes low flow area's.

How old is the tank?

 

[ReefToad]

IMO they should be at the correct par level for 8-10 hours.

I would not blame lights for algae, we all use lights in this hobby but we don't all have algae problems.

Corals browning out is usually due to lower light levels or increased nutrients. Since you have algae, I am also leaning towards increased nutrients. What are the nitrate and phosphate levels?

Do you have enough water movement in the tank? Algae likes low flow area's.

How old is the tank?

Nitrates are at 20ppm and phosphate is near 0. I have a HOB filter as well as a powehead creating circulation in opposing directions. The only corals that are browning are the two sps corals I have but calcium is roughly 580. Ammonia and nitrite are at 0 so no toxins. The tank has been running for 9 months roughly. It had some hair algae but that's cleared out and now it's mainly some cyano and possibly dinoflagellates. I feed a tiny pinch of either flakes or pellets for the fish twice daily, and I mean very tiny pinch, and I feed the corals twice weekly with a blend of various plankton, pods etc both live and dried.