# Too much Phosphate = Cyano and no GDA



## Glouglou (Feb 21, 2006)

After dosing PO4 to generously I end up with around 5 mg/l for 2 or 3 weeks.
Observation: No Cyano, GSA still coming on the glass, somehow in lesser proportion from before...


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## hoppycalif (Apr 7, 2005)

Too much phosphate doesn't equal GDA. I used to get GDA before I dosed any fertilizers at all. I don't think anyone knows just what does trigger GDA, but adding a lot of phosphate just hasn't been shown to start any algae growing.


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## MatPat (Mar 22, 2004)

I agree with Hoppy. If you are getting algae when dosing PO4 I believe it is moe than likely due to a deficiency in NO3. PO4 seems to increase the uptake rate of NO3 when plants are deficient in PO4 causing the tank to use a lot more NO3 than expected.


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## Glouglou (Feb 21, 2006)

*Thanks!*

I just post this to point out that lot of people think that adding phosphate will decrease green algae and induce cyano. It's possible, but not in this case. Maybe 3 week is to short for being sure.

Anyway the growth speedup at first but now this imbalance start to actually slow it down.

My KNO3 stay around 8 to 9 mg/l for the 3 weeks.


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