I moved the tank into my new house a few months ago, but this was happening at the other house as well. When I moved it I added a 1-2 inch sandbed and have had brown algae on it since. its been going away though, especially when I change the gfo. the glass stays clean, i use the mag float maybe once a week.
I agree w/ reefman especially considering the brown algae accumulation. Your nutrient level may be higher than you suspect despite testing- this can effect water clarity and light penetration.
Based on the above, what brand gfo are you using? BRS calls for 1tbsp per 4 gallons so 3-4tbsp that you are using sounds low...how often do you change it?
Inevo- I took your suggestion and moved my daytime light back another 45 min. Ill see how that does and go from there.
Im using BRS GFO and BRS ROX carbon. Iv never used that much GFO trying to be cautious. The water seems crystal clear to me. I will admit, its a PITA to change so I get around to it once a month.
I try and do every 6 weeks. For my calculated 72gallon water volume. I use 17 tbsp. if you are going to use less then recommended you need to change more often. It's definitely good to take it slow. Add a tbsp every time you change it. See if any positive or negative reaction.
Well those aquarium village lights are crap... Also there are some folks who will make pretty big stretches to find faults in LEDs. However, without specifics on your parameters, I am taking some guesses based on some other very familiar sounding clues in this thread...
I am guessing your nitrates are zero. When my nitrates were zero, I had no growth in my zoas and my sps would take on a flourecent green hue...particularly in the encrusting. Is your growth slow as well on the sps?
When my nitrates were zero I had all of these issues. For a year and a half i tried different things to correct them. Then I started feeding heavily to get my nitrates up and my growth took off....the color took about 7 months on most of the frags to return. But in 6 months my tank completely transformed. In color and growth.
That being said, I would suggests full spectrum fixture with 3 watt LEDs. Get your nitrates into the detectable and hold on and be patient...
The thing with GFO, you have to be cautious because it can pull to much to fast, and stress the system out, it has to be done slowly until the nutrient level stabilizes. I started with small amounts of GFO as well and slowly increased every few weeks. I was using BRS, but have since swapped to Continuum.