NPK balancing two products

PhenoMenal

Well-Known Member
I have a bottle of liquid guano which is 1-9-1, the instructions say use "5-10ml per liter".
I also have a packet of soluble powder Sulphate of Potash (potassium sulphate), 0-0-41, which says "dissolve 20g in 8L of water (2.5gm/L)"

I'm trying to figure out how much Potash I need to add with the guano to bring the resulting NPK from 1-9-1 to something better for bloom like 1-9-9 ? this is for hydroponics. (I also have a 4-0-0 CalMag if there's not enough N there!)
 

OldMedUser

Well-Known Member
You're never going to get a decent balance using those 3 things. You can't use enough of that CalMag to make up the N without overdosing on Ca and Mg. None of those will have a proper balance of micro-nutrients either so whatever you grow with them will end up sick and crappy.

There are decently balanced dry nutes you can get and they don't cost much. I'm sure a search here and on the interweb will give you all sorts of lo-cost solutions.

Good luck.
 

PhenoMenal

Well-Known Member
the CalMag is Flairform's CMX which also has micronutrients. The guano itself also has micronutrients. Haven't had any deficiency issues yet. This is for flowering anyway so I'm not in need of much N and the guano already has some

Anyway does anyone know how to get from 1-9-1 to ~1-9-9 by adding 0-0-41 potash?
 

PhenoMenal

Well-Known Member
THANKYOU for answers! exactly what I was after
But - is that per liter or gallon of reservoir water or...? (i use 10L of water)
 
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PhenoMenal

Well-Known Member
perfect (apart from imperial -> metric conversion requirement haha - and I'll assume that's US gallons and not UK lol), THANKYOU! :)
 

PhenoMenal

Well-Known Member
btw how did you guys figure this out? like an Excel spreadsheet or a particular nutrient calculator or just hardcore maths and a calculator or ... ? :) I would like to be able to make these calculations myself rather than having to ask!

I'm especially curious about how the calculation of powder is different to liquid in respect to converting NPK to PPM ???
 
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