Tank 55 gallon Sump 10 gallon 2 165 W LEDs SCA 301 Skimmer Danner 700gph return pump 200 micron filter sock 2 hydor koralia 1150's 50 pounds dry rock 3-4 pounds live rock from lfs 40 pounds arag-alive reef sand RO/DI unit to make water for ATO Filled tank and ran with just freshwater for a month, testing my DIY overflow and return. Mixed to salt around Aug 12th. All params in check, I added the live rock and 1 green star polyp frag on Aug 21st. GSP was doing great all visible polyps extending with bright green color. Started seeing the dark brown algae mostly on the tips of the rock work which was directly taking the light. After a couple more days started seeing little air bubbles coming from the algae. This morning the algae had started covering half of my GSP and needless to say that half is not extending anymore. I am seeing some on the sand bed and the live rock has much more on it than the dry rock as well. The live rock had nothing brown on it when I got it from the LFS. I was running blues at 25% from 12:00 - 23:00 and the whites at 50% from 15:00 - 21:30. I changed that schedule this morning to blues at 50% from 13:00 - 22:30 and whites at 25% from 16:30 - 21:00. Params currently sitting at SG 1.023, temp 78, ph 7.74(always been this low, no changes), 9 dKH, NH3 0, NO2 0, NO3 ~5, PO4 0, Calcium 440. I don't have the other element test kits yet. Have yet to buy any clean up crew as I had nothing for them to eat and didn't want anything to die if I could help it. Bad news is I leave in two days for a little over a week. I can monitor most of the stuff while away through the Apex but obviously I won't be able to do much. I'm thinking this is just the normal cycle for such a new tank and it will pass? Well I guess hoping is a better description or else I wouldn't be here asking. I have some pics but they are not so great with just the blues on. I did my best.