Hello, It has been awhile since my last post on this forum but I am on my third tank and this time running the full ZEOvit system. I have a 120 gallon display with a corner overflow. The filtration is in a 30 gallon breeder with a filter sock, ATI PowerCone IS-250 protein skimmer and Vertex RX-Z 1.5 Liter ZEOvit reactor with about 750 mL of ZEOliths. I do run ROX 0.8 carbon and GFO in separate mesh bags in the sump. I also dose lanthanum chloride as needed to lower PO4. I have a Jebao DC 6000 return pump and one Jebao RW-15 powerhead in the display. I originally dried the live rock out for three days and re-cured it for the 14 day initial ZEO cycle with no major issues. The tank has been up and running for 5 months now and the live rocks are completely covered with long strains of green hair algae and now I am beginning to have cyanobacteria growth on the sand bed. I have mix of Tonga, Pukani and Kaelini live rock which is about 100 pounds and 60 pounds of Tropic Eden Reefflakes sand. I was following the ZEO dosing schedule to the T until I started seeing the algae take over and now I have backed off to basically dosing only bacteria. I was dosing ZEObak, ZEOstart3, ZEOfood7, Sponge Power and KZ Coral Snow. I have also tried ZEOzym and mixing up the bacteria sources by using Microbacter7 and Special Blend. I have an assortment of Turbo Snails, Cerith Snails, Queen Conch, Blue Leg Hermit Crabs and now even a Sea Hare to rid the hair algae but nothing will touch it. I have three fairy wrasse's, one tailspot blenny, and two anthias in the tank. Maybe a tang would eat the algae? I feed frozen food twice a week but the fish mostly eat pellet food once or twice a day. I was thinking maybe the live rock is leaching out nutrients which is why only the rocks have green hair algae and not the overflow or glass/substrate. I try to stick with performing 30 gallon water changes with Tropic Marin Pro Reef sea salt and I do use a automatic doser to balance my alkalinity and calcium. My current parameters are as follows: Salinity: 1.025 (33 ppt) pH: 8.1 Alkalinity: 8 dKH Calcium: 420 Magnesium: 1380 Potassium: 380 Nitrate: 2.5 Phosphate: 0.05 ppm I have stopped dosing ZEOstart3 because I do register nitrates when I test and I don't want to fuel my algae bloom further. I currently run two 250 watt Phoenix 14K metal halides for 5 hours a day (3 month old bulbs) and two 54 watt ATI Pure Actinic T5's for 9 hours a day (3 months old). The first day I added the Sea Hare it ate a good amount of the algae on one portion of live rock but ever since it only hides during the day or berries under the sand, I haven't seen it eat anything. From the lack of ZEO dosing and lowering my nutrients I do seen a lightening in my SPS corals and they seem to really be suffering from all of this, not only from the lack of additives but also the algae stressing the bases of the corals. I try to brush as much of the algae off with a toothbrush but it grows back in two days. I even tried leaving the tank dark for three days but it did not kill the green hair algae just the cyano. Maybe the rocks will take a full year before they are gone leaching into the water column fueling the hair algae? Please help me as I am almost ready to give up out of frustration.