blue green algae AKA cyanobacteria

[happi]

i just realize that it might be GDA,looks similar to cyno in my tank. this is not my pic but this is what exactly happening in my tank.

http://www.aquascapingworld.com/thre...o-fix-it.1541/

[discuspaul]

If it is in fact green dust algae, i.e. it's mostly on the glass of the tank and is easily wiped off - then a UV sterilizer will deal with all of it that you can get free-floating into the water column. I got rid of it by wiping it off daily for several days in a row, so that the bulk of it was into the water and the UV could pick it up & zap it.
You still have to remedy the problem long term by determining the root causes & dealing with that, but the UV will kill off all the free-floating material it can take in via it's in-take filtering process.

[Capsaicin_MFK]

I had no fish in my 10g and I had a bad infestation of BGA from a botched DSM, so I triple dosed EM with no affect to the BGA. I tried a 4 day blackout and it didn't work either. The only thing that worked was spot treating with H2o2. If oxidizing is an issue, you could always try Potassium permanganate.

[plantbrain]

Originally Posted by happi

i just realize that it might be GDA,looks similar to cyno in my tank. this is not my pic but this is what exactly happening in my tank.

http://www.aquascapingworld.com/thre...o-fix-it.1541/

Then EM will not work.
I had several folks try EM on GDA at Sewingsalot' report that it worked.
It did nothing for several aquariums with it when those folks tried it.

GDA is an oddity.

Lowering light, so called brown outs does effect it.
I tend to not like those and try other approaches 1st. Blackout for 3 days only works on BGA, Green algae might grow slower, but when you increase light back up, just like the plants, they take off again. Algaefix seems to have killed some folk's cases, but others report it had little effect.

If you lack a real dense amount of plant biomass and have a lot of light, this also seems to be asking for GDA ISSUES. Some folks go months with it. I suppose I've been very lucky as all the cases I had lasted only a 3-4 weeks.
But it made testing it problematic, and inoculation seems impossible in a well run tank near as I can tell.

If it's GDA, then you'll need a different approach for sure, BGA, easy to get rid, folks have spent months with GDA.

H2O2 etc will do nothing to GDA.