Usually I run my lights 8 hours, but for a time I cut back to about 4 hours per day. I've never tested for phosphates in my tank but I keep my nitrates low, so I don't believe that's the problem. I'll have to look into a test kit for phosphates.
Jc1119;5150269; said:Try around 6 hours light and see what happens. i
TahoeFish;5150291; said:You've got blue green algae (cynobacteria) which is actually a collection of bacteria that can photosynthesized. I had a problem as well and tried all the typical stuff that you have tried. I then cleaned the tank as best I could by hand and did a full regiment of erythromycin (sorry if that is spelled wrong). It is available in the US under the API brand among others. Did not affect my filters, but I will leave it to you to read up on this. I have been algae free for 2 months now.
Good luck.
TahoeFish;5150326; said:I'm referring to just plain old erythromycin, an anti-biotic that is available in fish stores in the US. API is only one brand. I'm sure there are others. I don't know what is in algaefix. Google blue green algae aquarium erythromycin for info on treatment.
Did not harm my fish or my filter, but there is a risk to the filter but this antibiotic attacks gram positive bacteria and most of the good bacteria is gram negative or so I read here...
http://www.myfishtank.net/articles/blue-green-algae-article/
I did take my snails out however. Use it as directed and you should be fine. I hesitate totally backing it because I am new to the hobby. But I hated that algae and now it is gone.