By dosing PPS-Classic I began testing daily for two weeks.
Trying to get a feel for fertilizer uptake by plants.
My tank has enough NO3 due to bioload.
WC's were based on rising NO3.
By measuring I found PO4 to be near zero.
As increased dosing of PO4 occurred more NO3 was consumed.
To a point now where I need to dose NO3.
I never tried to measure K and kits for such are notably unreliable.
Measuring Ca and calculating the Mg content also helped.
Plenty of Calcium but plants were sucking up all Mg.
Needed to prepare this and begin dosing, now @ 5ppm.
I have also done much LED experimenting.
Recently traded 6-UV385nm 3 watt LED's with 6-Full Spectrum 3 watt LED's.
The full spectrum channel although dimmed and color not as appealing has promoted much more growth.