I usually see cyanobacteria as a symptom, meaning there is a imbalance somewhere, could be the wrong kind of light, could be overload of certain nutrients, so I never use antibiotics, for fear or creating resistant strains of pathogenic bacteria.
I had a plethora of the slime on one tank that got a few hours of afternoon sun.
I tried shade, more water changes, but in the end the only thing that worked effectively in removing it for good, was a regime of rid-X as a producer of different bacteria, that outcompete the cyanobacteria for whatever it was, allowing it to proliferate.
After a couple weeks of Rid-X, the cyan almost disappeared.
200 watts of led lights on for 16 hrs a day to get a heavy algea growth started on new coral decorations.
I have them dialed down once I noticed some cynobacteria growing. I had a mild outbreak 2 years ago.. It resolved it's self.
I have algea refugium going 24/7 @ 100 watts led that only grows long strand turf algea.
Rid ex idea I will have to check it out.
I was hoping to dose antibiotics long enouph to sterilize the tank, relying on algea scrubbers to do all the biofiltering.
I have some home work to do.
I had mats of cyano covering one of my tanks, water changes, blackouts, changing the lighting, stopping feeding, nothing helped. I'd clean every bit I could find and it would be smothered in cyano again within a week.
One round of Erythromycin and it never came back.
Also, I kept testing the water after dosing. No noticeable ammonia at any point.
Hello; Over the years had cyanobacter algae. Tried the EM (erythromycin). Kinda worked but did come back. A few years ago had it in my three set up tanks. Too many gallons to treat with EM in terms of cost effectiveness and as Duanes points out the risk of making a strain resistant to the EM.
I got rid of it and did it a very hard way. Did one tank at a time.
Emptied a tank of plants and fish.
Put the fish into a fourth holding tank.
Put the live plants into five gallon buckets with a strong dose of EM and left them a few days. Used a lot less EM that way and had the dose up to more lethal levels.
Cleaned a tank well and filled it with a water and Clorox solution.
Put all nets and other tank equipment in buckets with a Clorox solution. ( be sure not to use disinfected stuff around tanks not yet cleaned. Have two sets of nets and things. One set for the untreated tanks and another for the treated)
Once everything was cleaned, treated and disinfected I set up a tank. Had some prime on hand to neutralize the Clorox. I was not sure if the fish would carry the cyanobacter. I decided not to expose the fish to the EM and turns out they did not carry the cyanobacter.
Had to start the first clean tank from scratch in terms of a cycle as I was not willing to seed it from the infected tanks. After the first tank was clean and set up I did the other two.
I was more careful after all this with light cycle and feeding. Had I known of the Rid-X idea would have tried that first. I have done Rid-X since and it works or at least does not cause problems. My tanks are free of the algae for years now.
Discovered that the wave maker on the right side jammed up. Leaving a pile of detris in a dead zone.
Nitrates are below 20ppm I have dropped them from 40 ish to below 15ppm over the last 3 weeks.
The new lights were installed about 2 weeks ago. I have been using one on my top tank for about 6 months without any cyno growing only nice green short strand algea.
The lights have increased the water temprature from 72 to 76.
The refugium contains a basket ball size mass of long strand turf algea.
Fitltration consist of a 250 micon sieve screen followed by 200 micron nylon mesh socks changed out about 6 times per month. No substrate except tiles.
220 gallons total volume. 20 adult Malwai cichilds with about 20 juveniles less than 2" long.
The smoking gun. In January I laid my water changing barrels on their sides. In order to make room for my hydroponics growing area.
The drums were back tilted a little so about 4 gallons of sludge would not flush out during water changes.
The 55 gallons slow trickles thru my refugium then into the main tank. I think my phosphates got too high causing the blue green cyno out break.
Reshimed the drum about 4 degrees towards the drain. The 2" caps are easy to remove and flush out the drum without too much hassle.