are you confusing one calculator for another?
seamchems calculator is setup for seachem product bottle concentration.
to dose according to any given volume of water
EI dosage calculators are set up for the given concentration
you'ed mix the dry ferts into a 500 ml bottle. and dose accordingly to any given volume of water.to achieve a given ppm.
I dose all seachem and use their recommendation chart.
another thing seachem assumes a 5% weekly water change.
EI dosing assumes a 50% weekly "reset" water change, and an over abundance of nutrients.
seachem may be set up to mimic a weekly macro & micro offset daily
dosing. but not the EI concentrations
I am talking about this calculator http://calc.petalphile.com/
I chose "premixed fertiliser" and then ,the Seachem P and K ,to calculate for the EI/low light weekly.Since we cannot measure the K in our tanks ,I tried to measure the PO4 ,right after dosing(1 ppm according to the calc) ,and then ,measure in the end of the week ,right before the water change.I know that tests aren't accurate ,I just wanted to make an idea about the uptake.
In the end of the week the tests still showed PO4 being present ,but the color was really light (0.2-0.4 ppm) - to say it in numbers.
Which means I can safely lower my dosing ,until the test shows almost no PO4 before the water change ,right?and ,of course ,keep an eye on the plants ,and read their signals - better than any test ,from what I hear ,and makes sense.
That way I will find that so called "critical point" that people talk about when using the low light/no Co2 method.From there ,I can safely begin to postpone WC ,until maybe ,once a month ,or once every 2 months.
I may be wrong about this ,that's why I need help ,to make sure what I intend to do is right.Feel free to chime in.