Question about carbon dosing

[Eddie7144]

Ok so I'm thinking of carbon dosing to bring down my nitrates and phosphates. And I dont want to dose for anything I cant test/measure. My nitrates are at about 10 but my issue phosphates. I test it using hannah and salifert bot read at zero. But I have GHA in the tank. Now I know the algea is sucking up the po4, but if I cant measure it how can I dose for it ?

 

[NS Mike D]

certain nuisance algae and bacteria can get Phosphate from other sources- very common for cyano to appear when low to zero PO4 adn NO3 present.

One thing, if you do dose PO4 (there are threads in the reef chemistry forum on how to dose), you may not need to carbon dose as your corals may be better able to metabolize the NO3 with the addition of PO4 in the tank. In other words, the lack of PO4 might be limiting the corals zooxanthellae from photosynthesizing and thus leaving NO3 in the water for the nuisance algae/bacteria