Reefing newb
I have cyanobacteria growing all over my rocks, sand, and even some of my corals, I can not get rid of it. Can somebody please help me, I'm worried that it will suffocate my corals and stunt their growth. My light is brand new (bought it 3 months ago), I have a skimmer, 2 power heads on same side of tank, uv sterilizer, and a canister filter. I do water changes of 10% every week, testing every week, (all level perfect), and feedings twice a day. I was feeding every other day up until a month ago when I got 4 sea horses that require more feeding. I target feed my rtba and a couple of my corals. I also have 1 royal blue tang, 2 clown fish, and a goby (I think it's a green mandarin) 1 sand sifting star fish and another star fish that I can not remember the name of but it's a really skinny star fish that stays under the rocks and only comes out during feeding time (also target feed) about 30-35 lbs of live rock and a deep sand bed. I have cleaned and scraped the algae off the rocks, vacuumed the sand, and also vacuumed and sucked the algae up as I scrap it off. It's very easy to remove but it keeps growing back more and more every time I disturb it. I can't win with this stuff anybody have any good suggestions in how to get rid of it
My tank is 60 gallons and I just did a test tonight on my tank actually and these are my results
nitrate-40 ( I know way too high and I am doing a water change tomorrow mixing the salt as I type this, water change will be first thing tomorrow morning) (this is the first time my nitrates have been this high)
calcium- 400ppm
kh- 140-200ppm
phosphate- 0.25
temp- 78 degrees F
salinity- 1.026
I have never had a problem with cyanobacteria until just recently and its rapidly taking over everything in my tank all of my live rock is pretty much covered in it.
I have 2 powerheads, a uv sterilizer, a fluval 305 canister filter, a protein skimmer I cant remember the name of it.
I have 2 clown fish, 1 royal blue tank, a rtba, a sand sifting star fish, another star fish that I can not for the life of me remember the name of, a couple hermit crabs, a manderain goby, a few snails, 1 shrimp my other one died, 1 turbo snail, some coral, and just recently added 4 sea horse. ( yes, I know that is not a good idea to add the sea horses to my tank with the tank mates that I have in it, they are temp in tank only until my sea horse only tank finishes cycling. We only took them bc a friend we have had them and wasnt able to keep them, they were offered to us, we set up another tank to put them in but something happened and our friend had to get rid of them asap, since their tank wasnt finished cycling we put them in our display tank only until their tank is finished cycling then they will be removed into their own tank. We are about a week away from the tank being fully cycled) could the addition of the sea horse be the reason for the cyanobacteria?
Are you using an RO filter for your new saltwater? Got a TDS meter? Replaced your membrane(s) lately?

I personally would ditch the canister filter as a normal part of your biological filtration system. It's a nitrate factory. Best to use a canister for chemical filtration only. Run it for a week, then remove or change media. Lots of people run chemi pure or carbon.
I used to use activated carbon in my canister filter. It works great to polish your water and remove nitrates. Change that carbon weekly. Run it until the cyano is gone.

Then set the canister aside. Don't use it for biological filtration. It's a temporary pump that holds chemical filtration media in socks or mesh bags. That's all its good for.