Monopotassium Phosphate (MPK) vs Potassium Phosphate (K)?

calvin.m16

calvin.m16

Well-Known Member
What are the major differences between Monopotassium Phosphate and Potassium Phosphate?

I notice some nutrient lines will recommend running MPK start to finish of bloom whereas other lines will cut the MPK and have you switch to a standard Potassium Phosphate booster..

Any input would be great, I wasn't able to find a thread that discussed this in detail yet..
 
jondamon

jondamon

Well-Known Member
calvin.m16 said:
What are the major differences between Monopotassium Phosphate and Potassium Phosphate?

I notice some nutrient lines will recommend running MPK start to finish of bloom whereas other lines will cut the MPK and have you switch to a standard Potassium Phosphate booster..

Any input would be great, I wasn't able to find a thread that discussed this in detail yet..
Click to expand...
Someone who may know more is @xtsho about the differences for our applications etc.


I will admit that I use MKP and I use it diluted into water.

mixed at 14g per 100ml of water as a concentrate, allows an EC increase of 0.1EC for 1ml in 1litre of solution.

I use it gradually from around week 4 of 12/12 at low dilution. Building up to 1ml per litre of solution by week 6/7 then backing off.

i also use some Epsom salts during this time also for additional sulphur and Mg.

I can’t say what the differences are personally other than the MKP has replaced my “expensive” PK booster that my base nute line sells.
 
calvin.m16

calvin.m16

Well-Known Member
Thanks for the responses guys, I guess MPK is just a more stable "PK booster".

FloraFlex Bulky B & Full Tilt have replaced CYCO Potash+, Swell, Suga Rush & Supa Stiky with great results @ 1 TBSP/5 gallons of water..

I've been running the Bulky B for weeks 2-3 of bloom then I switch to Full Tilt weeks 4-6 before going back to just CYCO Base.
 
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Offmymeds

Offmymeds

Well-Known Member
I've been using Jack's 3-2-1 & then adding MKP during flower. I've been adding the MKP last. Is that correct? I haven't seen any precipitates.
 
jimihendrix1

jimihendrix1

Well-Known Member
In an 8 weeks flowering you only really need to use MPK in weeks 3-6. When buds set, and mid flowering. If you miss this window, MPK is useless. And in weeks 4-6 they can use an extra Epsom Salts boost.

The people at Hydro Gardens, whos fertilizer I use, and who have been in business since 1968, and making fertilizer since the 70s, and plant specific fertilizer since the 80s also says according to their studies with tissue culture, weed likes 2x the amount for Potassium than either Nitrogen, or Phosphorus.

Their base formula is 4-20-39, then add Calcium Nitrate, 15.5-0-0 and Epsom Salts. Then MPK in weeks 3-6.


CHEM-GRO 4-20 HYDROPONIC 4-20-39
Mixing Instructions per 1 gallon of water
(For full strength working solution)​

4-20-39 Recipe – For a great baseline would be 2 grams per gallon of 4-20-39, 2 grams per gallon of CaNO3 and 2/3 that amount of MgSO4 (1 1/3 gram per gallon). We suggest you try to keep your pH right around 6.2 for the duration but some fluctuations are not uncommon. During middle weeks of flower, you can add 1/3 the amount of MKP for extra K (potassium). Certain strains can tolerate a higher EC than others and you are welcome to push those strains if you like but we feel the base mixture will do a great job,

Designed for Hemp/Cannabis growing hydroponically​
 
Star Dog

Star Dog

Well-Known Member
jimihendrix1 said:
In an 8 weeks flowering you only really need to use MPK in weeks 3-6. When buds set, and mid flowering. If you miss this window, MPK is useless. And in weeks 4-6 they can use an extra Epsom Salts boost.

The people at Hydro Gardens, whos fertilizer I use, and who have been in business since 1968, and making fertilizer since the 70s, and plant specific fertilizer since the 80s also says according to their studies with tissue culture, weed likes 2x the amount for Potassium than either Nitrogen, or Phosphorus.

Their base formula is 4-20-39, then add Calcium Nitrate, 15.5-0-0 and Epsom Salts. Then MPK in weeks 3-6.


CHEM-GRO 4-20 HYDROPONIC 4-20-39
Mixing Instructions per 1 gallon of water
(For full strength working solution)​

4-20-39 Recipe – For a great baseline would be 2 grams per gallon of 4-20-39, 2 grams per gallon of CaNO3 and 2/3 that amount of MgSO4 (1 1/3 gram per gallon). We suggest you try to keep your pH right around 6.2 for the duration but some fluctuations are not uncommon. During middle weeks of flower, you can add 1/3 the amount of MKP for extra K (potassium). Certain strains can tolerate a higher EC than others and you are welcome to push those strains if you like but we feel the base mixture will do a great job,

Designed for Hemp/Cannabis growing hydroponically​
Click to expand...
What ec would you add of mpk, iirc the npk is around 50-33pk I'd need to double check the exact ratio but it's thereabouts.
I bought some last month and I'm just starting the 3rd week 12-12.
 
jimihendrix1

jimihendrix1

Well-Known Member
1/3 strength of the base formula Not sure of the exact EC. I just weigh it out. I use 2 grams per 5 gallons of water of 4-20-39. 2 Grams of 15.5-0-0, .66 grams of MPK and 1.33 grams Epsom Salts.

I feed at every watering. My medium is Promix BX.

This is also for a plant at 2 weeks after flip. I use less from seedling-veg, and slowly increase weekly from seedling - veg until giving the maximum dose in week 2-3 after flip. I may use 1/4-3/4 of this amount from seedling- veg
 
Star Dog

Star Dog

Well-Known Member
jimihendrix1 said:
1/3 strength of the base formula Not sure of the exact EC. I just weigh it out. I use 2 grams per 5 gallons of water of 4-20-39. 2 Grams of 15.5-0-0, .66 grams of MPK and 1.33 grams Epsom Salts.

I feed at every watering. My medium is Promix BX.

This is also for a plant at 2 weeks after flip. I use less from seedling-veg, and slowly increase weekly from seedling - veg until giving the maximum dose in week 2-3 after flip. I may use 1/4-3/4 of this amount from seedling- veg
Click to expand...
Thanks for this bud I'll give that a try, my plants have just started that hungry af phase the ec run off was getting down to 30/35% lower than going in on every feed, on my last crop it didn't level out until I hit 2.0/2.1.
 
Star Dog

Star Dog

Well-Known Member
jimihendrix1 said:
1/3 strength of the base formula Not sure of the exact EC. I just weigh it out. I use 2 grams per 5 gallons of water of 4-20-39. 2 Grams of 15.5-0-0, .66 grams of MPK and 1.33 grams Epsom Salts.

I feed at every watering. My medium is Promix BX.

This is also for a plant at 2 weeks after flip. I use less from seedling-veg, and slowly increase weekly from seedling - veg until giving the maximum dose in week 2-3 after flip. I may use 1/4-3/4 of this amount from seedling- veg
Click to expand...
Sorry could I double check before I mix mkp up, that's 1/3 mkp of the total nutrient strength?

Cheers
 
jondamon

jondamon

Well-Known Member
Star Dog said:
Sorry could I double check before I mix mkp up, that's 1/3 mkp of the total nutrient strength?

Cheers
Click to expand...

mix up the concentrate like I did buddy it’s much easier to dose with.

100ml water to 14g MKP dissolved.

add at 1ml per litre and it increases EC by 0.1.
 
jimihendrix1

jimihendrix1

Well-Known Member
Heres where I get my info on how much to mix.


Notice they add Calcium Nitrate 15.5-0-0 and Epsom salts to the mix. They give measurement for each individual nutrient for both base formula, and Calcium Nitrate. Which is 2 grams individually. So I assume the recommendation for MPK would also go by per individual recommendation. Which is 2 grams. 1/3 of 2 grams is .66 grams.


CHEM-GRO 4-20 HYDROPONIC 4-20-39
Mixing Instructions per 1 gallon of water
(For full strength working solution)​

4-20-39 Recipe – For a great baseline would be 2 grams per gallon of 4-20-39, 2 grams per gallon of CaNO3 and 2/3 that amount of MgSO4 (1 1/3 gram per gallon). We suggest you try to keep your pH right around 6.2 for the duration but some fluctuations are not uncommon. During middle weeks of flower, you can add 1/3 the amount of MKP for extra K (potassium). Certain strains can tolerate a higher EC than others and you are welcome to push those strains if you like but we feel the base mixture will do a great job,

Designed for Hemp/Cannabis growing hydroponically​
 
Star Dog

Star Dog

Well-Known Member
jondamon said:
mix up the concentrate like I did buddy it’s much easier to dose with.

100ml water to 14g MKP dissolved.

add at 1ml per litre and it increases EC by 0.1.
Click to expand...
I wrote down that ratio when you posted it a few weeks back that's how I intend to use it on the bulk of the crop.

I'm not big on additives normally but I've a golden opportunity to test a plant or two with elevated levels of pk, camcium/magnesium etc.

I intended to try that ghs gift pack but it's too much hassle feeding different nutrients I'd need to set up another reservoir, pipe work, pump etc it's not practical for me to do.
 
Star Dog

Star Dog

Well-Known Member
jimihendrix1 said:
Heres where I get my info on how much to mix.


Notice they add Calcium Nitrate 15.5-0-0 and Epsom salts to the mix. They give measurement for each individual nutrient for both base formula, and Calcium Nitrate. Which is 2 grams individually. So I assume the recommendation for MPK would also go by per individual recommendation. Which is 2 grams. 1/3 of 2 grams is .66 grams.


CHEM-GRO 4-20 HYDROPONIC 4-20-39
Mixing Instructions per 1 gallon of water
(For full strength working solution)​

4-20-39 Recipe – For a great baseline would be 2 grams per gallon of 4-20-39, 2 grams per gallon of CaNO3 and 2/3 that amount of MgSO4 (1 1/3 gram per gallon). We suggest you try to keep your pH right around 6.2 for the duration but some fluctuations are not uncommon. During middle weeks of flower, you can add 1/3 the amount of MKP for extra K (potassium). Certain strains can tolerate a higher EC than others and you are welcome to push those strains if you like but we feel the base mixture will do a great job,

Designed for Hemp/Cannabis growing hydroponically​
Click to expand...
Here's where I'm at, I've grown for many years but simply using a+b doing the same thing time after time, it's only recently I've started considering adding calcium/magnesium/mkp in powder form, I can use that with my ec truncheon to mix 0.1 increments.
You're using dry powder which I cant relate to, to covert if that makes sense to you.
 
jimihendrix1

jimihendrix1

Well-Known Member
Yes Im using Dry mix. I dont know the conversion rate. I also get my Calcium from Calcium Nitrate, which is 20% Calcium. WHich negates my need for Cal/Mag as I get my Magnesium from Epsom Salts, as well as Sulfur.
 
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