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.
- The other hobby
No planted tanks currently running (11/26/2014)