Question about Spectracide Nitrate dosing (and Phosphorus)

[Aquaman102]

I'm am prepping to defeat dino's (prorocentrum) by dosing Spectracide (Nitrates) and Seachem Phosphorus)

The Spectracide is in powder form. Do I just pour a bit in and test after a while to see how much the nitrates increase? Is there a rule around adding X amount of Spectracide to make Nitrates increase by Y amount?

 

[nezw0001]

you might want to post this in the chemistry section. I'm sure someone can calculate it out for you.