Water change? Yes/No... Lesser of two evils

[Randy Holmes-Farley]

Im not really sure lol but ive had this same issue so many times, as soon as nitrate falls below phosphate, the po4 skyrockers and cyano it is ( for me) =) but yea the gfo seems to not work at all, it seems strange but it does happen

Sorry, it must be some other mechanism, such as other organisms that normally take up phosphate slowing their growth because they are N limited.

 

[Randy Holmes-Farley]

This is strange and doesn't really add up. GFO being a binder is not dependent on anything but its saturation point. So the more likely answer is that at the time of the WC the GFO is saturated and not absorbing phosphate, coupled with the lack of nitrate even the amount of phosphate used in the redfield ratio is not exported. So phosphate rises... It's the only logical explanation.

Yes, I agree. N limiting the growth of other organisms sounds likely.

 

[Lenny_S]

I would just couple a refresh of the GFO at the time of a water change. That will likely solve the issue and if it works, solve the mystery. [emoji6]

 

[Sabellafella]

Sorry, it must be some other mechanism, such as other organisms that normally take up phosphate slowing their growth because they are N limited.

Lolol the knowledge i learn from you mr randy