High Phosphates but no nitrates?

[Crabs McJones]

Im not overly concerned about ph. I have my doser set to dos alk around the clock, so ph stays up. But I have my fuge set to come on at 10pm and off at 6am

 

[Randy Holmes-Farley Verified Community Expert]

Didn’t say less light would lower phosphate. Said it would raise nitrates. Is there any scientific proof that raising nitrates could lower phosphate?
Kalk can help lower phosphate too. Pretty sure there’s no proven evidence of this but it is thought, and i’m A believer

There is certainly "scientific proof" that if an organism is nitrate limited in growth, that adding nitrate is going to make it grow faster, and that it must take up more phosphate. That is the very definition of what it means to be nitrogen limited. There's zero uncertainty that it can happen.

BUT, you seem to be extrapolating to a different scenario. If you cause the algae to grow less by using less light, it will use LESS N and P. I is no longer N limited (if it ever was), and that rise in nitrate cannot possibly cause a decrease in phosphate (at least by that same algae).

 

[Randy Holmes-Farley Verified Community Expert]

I feel less cheato would help more then less light because when you mess with the lighting if he runs his fuge at night to keep his ph up so then he will be dealing with ph issues if he’s on a reverse cycle

Less chaeto would help do what, exactly?

 

[Stickboy15]

Get nitrates up

 

[dwest]

Nitrate dosing would be a brand new field for me, any suggestions? ELI5

I nitrate “dose” by simply adding adding enough solid NaNO3 to raise the level 1 or 2 ppm. I only need to do this periodically in my system, about every month or so. I won’t let either po4 or no3 get to zero after my last dino fight.

I’ve also added nitrates with wc in the past, but get the same results by adding solid.

 

[BigJohnny]

Update? I'm in a similar situation. My nitrates were 16ppm and my phosphate .3 ppm. Lengthened my fuge photoperiod and now after a few months my nitrate is less than 4ppm and my phosphate is greater than 1ppm! Corals look stressed and whenever I try to run gfo, no matter how little or slow, they start to pale, even if my phosphate doesnt drop. I'm starting to think the imbalance of nitrate to phosphate (dont worry I'm not talking redfield ratio here) may be the issue and my corals need more nitrate before I can take phosphate down. Either that or my increased fuge photoperiod is pulling too much of something else out.