Daytime lighting hours

[bj5z25]

In my newly setup and cycled 75 gal reef I have a 260 watt pc lighting system. I have a lot of brow algae frowing on my substrate and tank walls. I usually leave the lights on for 12 hrs in the day and off for 12 hrs in the night. Is this too much lighting? is this why i have so much algae?

TIA

[Fluff]

the brown algae is probably diatoms and is typical in new tanks. I leave my lights on 10-12hrs a day. 10 hours with both daylight and actinic and two hours (one hour morning and night) of actinic alone. So, no I don't think it's to much light. Get a clean up crew for the diatoms and give them some time to burn themselves out.

[nsu7]

Cindy would you say that's enough light in a 75gal for LR, esp. for coraline algae on LR? I am looking to get the same lighting for my 75 gal...