Should I keep increasing my nopox doses?

Murraydar · Aug 24, 2020

Long story short, my phosphates are elevated (~.35ppm on hanna ulr) and refuse to budge from gfo and carbon dosing. My feeding is not excessive so I'm assuming its leeching from rocks or whatever. I am dosing diy nopox (50% vinegar, 35% vodka, 15% water) on a daily basis but my doses are getting scary big. I was up to 34ml before I stopped on a tank with ~80 gallons of water.

The nopox appears to be working, at least on nitrates. I have to dose kno3 daily to keep nitrates up but it doesnt seem to touch my po4. I am skimming fairly wet and emptying every other day. So my question is: do I keep increasing my doses until something happens? What is the risk of too much carbon dosing and what would an appropriate max dose be? If the po4 is leeching from rocks, do i find a comfortable dose and leave it there until something happens? Im hoping someone here has been in the same situation as i am. Thanks!

vetteguy53081 · Aug 24, 2020

NoPox. . . . alternative- not a solution. Utilize water changes to bring it down, reduce feeding quantity and clean/ change filters regularly

taricha · Aug 25, 2020

Murraydar said:
The nopox appears to be working, at least on nitrates. I have to dose kno3 daily to keep nitrates up but it doesnt seem to touch my po4. I am skimming fairly wet and emptying every other day. So my question is: do I keep increasing my doses until something happens?

The simplest issue here is that carbon dosing a Nitrogen limited tank will have a hard time lowering Phosphorus. So larger doses of carbon still won't help if the N is limiting.
If N and C are both provided, then biomass growth ought to lower PO4. (It sound's like skimming is working properly).
also I wouldn't aim to drop PO4 too fast. That's pretty difficult and may be a shock to the system.

Murraydar · Aug 25, 2020

taricha said:
The simplest issue here is that carbon dosing a Nitrogen limited tank will have a hard time lowering Phosphorus. So larger doses of carbon still won't help if the N is limiting.
If N and C are both provided, then biomass growth ought to lower PO4. (It sound's like skimming is working properly).
also I wouldn't aim to drop PO4 too fast. That's pretty difficult and may be a shock to the system.

Yeah that's my logic behind the nitrate dosing. I'm keeping it at around 10ppm. I imagine this should be enough to prevent any kind of limitations but I've read of people elevating it higher in order to get a better "ratio" of nitrogen to phosphorus but i don't know if there's any truth to that.