When calculating P and K...?

[Tomatoesonly]

When you are calculating P and K.. for something like hydrobuddy, the label may say "available P (P205) 10%".. ARe they saying the downgrade is already calculated in or do you still need to downgrade it because of the P205? I hope that makes sense.

 

[Arnold.]

P205 (phosphate) has 44% P (Phosporus)
K2O has 88% K
I seem to remember that hydrobuddy asks to converse it, no?

You can calculate it yourself for all the other things. Here's how:


So, for example, how many Ca- and S- does CaSO3 (gypsum) have?

You need a periodic table for that:



The atomic weights are: Ca=40, S = 32, O = 16.

We got 1 Ca atom, 1 S atom and 3 O atoms so the total weight of this molecule is 40 + 32 + 3x16 = 120.

How many percent of that total weight comes from S-? 32/120 = 26.7%

How many percent of that total weight comes from Ca-? 40/120 = 33,3%

 

[Tomatoesonly]

I don't understand why they use that number if it's basically bullshit... ?

 

[Gooseman23]

I don't understand why they use that number if it's basically bullshit... ?

Yea I’m hydro buddy when you are adding a new substance you will see an arrow right to the left of p and k that you can choose p205 and k20 and it will convert for you.

 

[Tomatoesonly]

Yea I’m hydro buddy when you are adding a new substance you will see an arrow right to the left of p and k that you can choose p205 and k20 and it will convert for you.

So that's just the way you should always do those numbers? Is there any nutes that give a number that's actually available or is it just a shell game? I've been reading articles on this and it's steeped in OLD BS from decades and decades ago.

 

[Gooseman23]

So that's just the way you should always do those numbers? Is there any nutes that give a number that's actually available or is it just a shell game? I've been reading articles on this and it's steeped in OLD BS from decades and decades ago.

Nah if you read the label it should say it on there.it will say:
Available phosphate (p205)……12%
It will read something like that. Not on the front of the nutes they just have NPK but usually on the back it will have specifics on the product label that will say that.

 

[awwwc]

Yea you should always check te label because there are ideal ratios to follow