New 73 gallon tank setup

[Frogger]

I tested my tank today after adding 10ml's of the KNO3 mixture I prepared twice a day for the past 3 days.

SG:1.026
NO3-still 0 not even a tint of pink
PO4-.01ppm
Temp- 80f
Ca-410ppm
Alk dkh-9.7
Mag-1410ppm
K-400ppm
I have been monitoring the tank closely for any signs of stress, algae growth or changes and have seen nothing. I was wondering about the test kit for nitrate so I tested it against a known value (.6ppm) for KNO3 mixed in RO water and the test kit was bang on.

Looks like I have to increase the KNO3 levels as my tank is using it up as fast as I can add it. (good thing). I will double my dosage rate and report back in a few days.

Seeing as I am adding a lot of KNO3 I have been looking for a purer source as I am concerned about what else is in my KNO3. I have found a chemical company in Vancouver area that sells reagent grade 500 grams of for $27. As 500 gram of the stuff would likely be enough to last me several years even at a much higher dose.

My goal is to create an equilibrium within my tank nitrate to phosphate of around 16 to 1. The amount of K in the solution will not even slightly affect the total K in the tank as we are talking about 400ppm as per the nitrate levels of less then 1ppm.