ncy

Hello!

Can anyone tell me if it makes sense to estimate what the concentrations of K & P are by using my Nitrate readings as a reference point? i.e. if my nitrate concentration is 5ppm and I'm adding daily

.059 grams K2SO4 (Potassium Sulfate)
.065 grams KNO3 (Potassium Nitrate)
.06 grams KH2PO4 (Mono Potassium Phosphate)

Which is equal to (according to fertilator)

1.05 ppm Nitrate
0.11 ppm Phosphate
1.14 ppm Potassium

Can I deduce that I currently have approximately 5 times the daily addition of P & K? Or is plant nutrient uptake too unpredictable to determine from the nitrate reading?

Also,
On the Fertilator here at APC, are the numbers below the calculation boxes suggested guidelines for nutrient levels to maintain in the tank?

ray-the-pilot

It is difficult to say what the levels of K and PO4 are based on Nitrate level alone.

That being said, my experience is that initially, KPN can be all over the place. You should test regularly for them when you start up an aquarium.
After about 3 months, K and N will gradually increase together while P will decline. Periodically, I add some PO4 only fert with no K or NO3 to bring down the K and NO3.

The numbers below the fertilator are suggested guidelines. You will probably be below those numbers when you start up with PPS pro but don't worry. Over time you will fall in almost exactly with the suggested levels.