DOS programing help

[Jamie814]

Hopefully someone can help me,
I am trying to program my DOS using advanced programing to stop dosing NoPox if my NO3 is less than 8ppm based on trident NP test, but the IF commanded does not give NO3 as an option. It has PO4 ,ALK, CA, MAG all showing as options when I search but no NO3....

I just don't understand why PO4 is control option but not NO3? The PO4 test is far more inaccurate.

 

[RoanokeReef]

Weird mine does -

 

[Jamie814]

Weird mine does -

Hmm, may have to contact Neptune

I only get the Sun or Moon when typing N

I've tried it on other channels as well and it does not come up as an option.