Making me crazy!! Freshwater cynobacteria

I would do the blackout in conjunction with the erythromyacin. Your discus will be fine for three or four days IMO. Check on your nitrates as well. I believe that's why I had it (too dilegent with my waterchanges combined with a moderately planted tank and no fert dosing)
 
I removed the part of plants where mine was growing on, and after getting the ferts right, the BGA just vanished. Perhaps, I was just lucky.

Kudos to you then, I could never get rid of it for about a year after I got it. I would manually scrape it off the plants/glass/gravel very often. It's supposed to appear when nitrates hit zero for an extended period of time but mine wouldn't go away with manual removal and a constant 10-20 nitrate reading.

I read to do a 3-4 day blackout and I suggest a 4 day. I blacked mine out for three and it didn't die.

On the other hand, it was super easy to use BGA remover with no blackout and results in one day.
 
I had a case of cyno in my 50g aquarium for about a year. Lots of water changes and manual removal along with a couple of 3 day blackouts help to control it, but never seemed to be able to get rid of the stuff.

I finally went with a five day treatment of erythromycin and after that it has stayed gone. Because of the dosage needed (one tablet per 10g) and the fact your looking at two different aquariums I wouldn't bother to buy the eight pill packs. Think of something like this one from bigals and you can save the rest of the tabs in case of a disease later.
 
B-G algae has always been the bane of my aquarium keeping. Probably because I, as it seems with others here, have been `too' good at de-nitrifying. Th eevidence does appear to be there that we (aquarists and the plants in our tanks) are better at doing this than phosphate removal. I have come across this Dutch web page that tries to solve the problem.
http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm

But in layman's terms, how can one easily add a bit of nitrate to an aquarium and/OR what plants are extra good at *phosphate* removal?
 
I dose Flourish Nitrogen at the moment, but I may switch to solid ferts. I don't remove phosphate, because the plants need it. It's just about getting the right balance.

Yes, BGA are phosphate hogs. I grow BGA at work, and have to replenish phosphate all the time ;).
 
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