Hello everyone, \n \nIt's been awhile since I've been on here but it's great to be back. I am here because I am just desperate for any new ideas on the long term issues I've been having. I've been doing saltwater for 8 years, so I am no newbie however apparently theres still something about water chemistry i just dont get. \n \nIf you name it, I've probably tried it...so I will lay it all out for you in detail and please read it thoroughly before throwing out ideas. \n \nSpecs: 29 gal reef (soft corals, 1 fish), RO/DI water, 54W blue/white LED lighting on for 6 hours a day, 18W royal blue/magenta LED lighting on for 3 hours a day, temp 78-80, powerheads: one at top, 1 maxijet1200 pumping water though a grid i have going all over my tank, 1 maxijet 400 pointed at the sand, reef octopus BH-100 protein skimmer, hang on tank aquaclear50 filter w carbon, phosphate reactor w/ ferric acid, water changes consistent every other week about 4 gallons. Feed fish every other day with rinsed frozen cubed food. Currently dosing: KENT calcium buffer system TECH CB parts A & B, KENT TECH M magnesium about every other day, trace elements, iodide, stronium and molybdenum once a week. Full of live rock and been set up for 1 1/2 years. Last time I checked my calcium is was 430. Cleanup crew: (i know i need to replenish, many have died since my last purchase) 1 turbo snail, 4 scarlett reef hermits, 1 electric blue hermit, 3 sand snails, 1 peppermint shrimp. \n \nHere's my ongoing problems: \n1) I have never, ever, in the history of my tanks in 8 years been able to get my PH above 8.0. In this small tank, it has been nearly impossible to get coraline algae growing, especially on the rocks. In my old 90 gal, which i had set up for 4 years, i eventually got lots of coraline growing (but then again i had a more powerful lighting system too). I just can't seem to get my PH up or coraline.... \n \n2) Cyanobacteria that just wont go away. I have used the chemicals (it barely clear it out and as soon as I stop the chemicals it comes back). I have tested my phosphates the test kids read 0. I have tested my RO/DI water for phosphates, they read 0. I have tried new test kits...they all say 0. I have tried increasing my water flow (hence the maxijet with grid system). I have noticed the cyano seems worse when i dose the magnesium (maybe I'm wrong) but ive been going easy on dosing that. It's ugly, just make it go away. \n \nWith all that said, please pose your questions and suggestions. On the brightside my soft corals are growing beautifully! My one hard coral, a bubble, was shipped to me and nearly died in shipping. It is fighting back fabulously which is another reason I am trying to keep the calcium levels up! Now lets just get that PH up and cyano gone!!\nTHank you all!!