Is "dissolvability" cumulative

Bill Stock wrote:
"Elaine T" wrote in message
...

Bill Stock wrote:

I decided to add Potassium and Magnesium to the last batch of "PMDD" I
mixed up to save me the trouble of adding it separately. But the amounts
I needed to add to my stock solution to reach Chuck Gadd's recommended
dosages were above the amount of each compound that would dissolve in my
stock solution. So I reduced the amounts to levels that should dissolve
in my stock solution, but they still did not stay in solution.

I gather these "dissolvability" numbers are cumulative and not specific
to each chemical? Is the cumulative effect straight line or does it
depend on the chemicals being dissolved.

Just curious.




Yes, the amount of solids you can add to a solution is cumulative. The
effect depends on the chemicals being dissolved and some even precipitate
out in combination, like calcium and phosphate.


Thanks Elaine, makes sense based on what I'm seeing.

I was hoping to increase K and Mg above the standard PMDD strength to avoid
adding extra doses separately. I guess I could increase the size of my stock
container and just add more solution each week to accomplish the same thing,
but a 10 gallon stock container might be a little impractical.



ROFL! I was stirring forever trying to get a Plantex and potash mix to
dissolve this afternoon. I kept adding more and more water - it's half
the strength that I wanted. *sigh* Is it just me or does it seem like
you have to add incredible volumes of PMDD to get decent amounts of
ferts in the water? I'm looking at 1.5 ml per 10 gal per day of my brew
to try Tom Barr's Estimative Index dosing.

--
Elaine T __
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