Monopotassium phosphate, MKP, as a fertilizer. 0-52-34 (99%+)

[Frankster]

Picked up 5 lbs of this tonight. ($25)I can't get enough amendments. LOL I like organics, but I love my chemistry as well.

Monopotassium phosphate, MKP, (also potassium dihydrogenphosphate, KDP, or monobasic potassium phosphate) is the inorganic compound with the formula KH2PO4. Together with dipotassium phosphate (K2HPO4.(H2O)x) it is often used as a fertilizer


Monopotassium phosphate can exist in several polymorphs. At room temperature it forms paraelectric crystals with tetragonal symmetry.

Monopotassium phosphate is produced by the action of phosphoric acid on potassium carbonate.

Ph is 6.8 so it's a weak acid. although if mixed with dipotassium phosphate which is a strong base, so it can be used for balancing pH. NPK Ratio: 0-52-34 (99%+)

Chemical formula	KH 2PO 4
Molar mass	136.086 g/mol
Appearance	White powder, deliquescent
Odor	Odorless
Density	2.338 g/cm3
Melting point	252.6 °C (486.7 °F; 525.8 K)
Boiling point	400 °C (752 °F; 673 K) , decomposes
Solubility in water	22.6 g/100 mL (20 °C) 83.5 g/100 mL (90 °C)
Solubility	Slightly soluble in ethanol
Acidity (pKa)	6.86[1]
Basicity (pKb)	11.9
Refractive index (nD)	1.4864

 

[cemchris]

Staple with most salt guys. Also keeps you from buying bloom boosters that charge you 10x or more for the same thing most of the time.

 

[Frankster]

Staple with most salt guys. Also keeps you from buying bloom boosters that charge you 10x or more for the same thing most of the time.

Thanks for the reassurance cemchris, this is what I was looking for with this post. Like I stated above, I like organics, but I also have a real affinity for chemical adjustments, especially for the end part of the program, where ph adjustments are required, or replenishment of certain nutrients are appropriate.

I would much rather use something that's functional, instead of simply adding in stuff that the plant can't use, so having both a acidic and base forms of both potassium and phosphorus seems key to that endeavor.

What are some of the most useful salts, or compounds to have on hand in your opinion? Do you use dipotassium phosphate or phosphoric acid?

Do you use any of the ammonium salts? or Urea? I think using urea might produce some Co2 byproducts (during uptake) that could possibly prove useful, but who knows the amounts, if they are only trace. But even traces should prove useful, especially with Co2

 

[Frankster]

Been doing a bit more research, looks like ammonium phosphate, potassium nitrate and ammonium nitrate are the other critical pieces to this puzzle, especially for the earlier flowering stages.

 

[Dr.Green55]

Calcium nitrate, potassium sulfate, potassium nitrate, mono potassium phosphate, magnesium sulfate plus micro nutrients generally make up the standard 6 pack. those salts can make a complete formula from start to finish, just adjust for stage of growth, and the quality of salts makes a difference as well.

 

[Aqua Man]

Yeah been using this for a long time. The more diverse selection of salts you have the easier it is to dial in your targets.

 

[Dr.Green55]

I personally don't use any ammonium or Urea products at all, a specially not on top of my 6 pack, I find they do more harm then good, but thats just me.

 

[cemchris]

Thanks for the reassurance cemchris, this is what I was looking for with this post. Like I stated above, I like organics, but I also have a real affinity for chemical adjustments, especially for the end part of the program, where ph adjustments are required, or replenishment of certain nutrients are appropriate.

I would much rather use something that's functional, instead of simply adding in stuff that the plant can't use, so having both a acidic and base forms of both potassium and phosphorus seems key to that endeavor.

What are some of the most useful salts, or compounds to have on hand in your opinion? Do you use dipotassium phosphate or phosphoric acid?

Do you use any of the ammonium salts? or Urea? I think using urea might produce some Co2 byproducts (during uptake) that could possibly prove useful, but who knows the amounts, if they are only trace. But even traces should prove useful, especially with Co2

NH4 you want to keep at 1:10 to N03 at the most unless you are growing in soil. Any type of soil less to water culture it's mostly used for PH. General rule of thumb is like 10-15 ppm at the most unless you are just blasting nutes.

Mag sulfate and cal nitrate are pretty big staples also. Go through those 2 the most weight wise. Pot nitrate, mag nitrate, & pot silica are also used but in way lower amounts then the others. I stay mostly on the nitrate side of things and dose heavy with mag sulfate. Using other sulfates would send S through the roof for me.

As far as NH4 I use MAP. I have kind of weened myself off of it some since its pretty incompatible with most concentrate mixes and just settling on a mix that is doser friendly. This is just more simplicity of cross over for other things. Not to mention the added mixing time when using it. Even dropping the P way down I have only seen positive effects no negs. Granted I was waaay low for a while and have brought it back up some. Still under 75 ppm.

Urea I avoid. You don't want anymore then traces.

I hit heavy with phos acid after pot silica since it puts the rez above a ph of 9.

I stay 100% salts and DTW because I don't want to play the check the rez ph everyday game anymore. Mine might move .1 over the span of 5 days.

 

[Frankster]

Calcium nitrate, potassium sulfate, potassium nitrate, mono potassium phosphate, magnesium sulfate plus micro nutrients generally make up the standard 6 pack. those salts can make a complete formula from start to finish, just adjust for stage of growth, and the quality of salts makes a difference as well.

don't you worry about sulfate accumulation?
after doing a bit of reading it appears sulfate is a little more important that I've appreciated in the past. It doesn't seem like a big deal, but it's needed for some hormones and protein synthesis.

 

[Frankster]

Yeah been using this for a long time. The more diverse selection of salts you have the easier it is to dial in your targets.

that's what I'm thinking also, so just getting standard amounts of various raw components, in the salts category and then I'll have everything on hand, for immediate uptake, in a shortage senario, allowing me to hit it through a few different channels.

Like now that I had been hitting them with that epsom salts and and cal mag for a few days,

Last night, I hit it with dolomite lime (all of them) and did a small foliar with humics, (few days ago) then I also added a bit of mildly strong base with potassium hydroxide flush, and a topped off the dolomite with a bit of triple phospate rock, that should take them into the flower well. I did a little more bone meal and kelp last week also. I've got some different potassium salts coming, even a bit of human urine is a good amendment, if done in proper proportions, TBH

Urine is very high in nitrogen (can be over 10% in a high-protein diet), low in phosphorus (1%), and moderate in potassium (2-3%)

 

[Frankster]

I personally don't use any ammonium or Urea products at all, a specially not on top of my 6 pack, I find they do more harm then good, but thats just me.

thanks, yea I was thinking about that, sounds like farmers use them because of cost constraints, and also for their longevity persistence, I suspect they may be useful in trace amounts, (early on) but the salts should be the mainstay of correcting any deficiencies. I want to remain well rounded with aminos, humics, even hormones in some cases. (especially during early flowering)

I'm also interested in maintaining my microbiology balance, so I need things that will be effective, but not too harsh, or wild ph changes, unless of course, that's the desired result. I just want "options" and to try different things, actually. Mischief, curiosity.

I want the salts more as a "choice" in my approach in the current format, a tool box to reach for when things need realignment.

 

[Dr.Green55]

Hey Frankster the best part about growing is there is a million different approaches one can take to grow really good plants, and the only thing that matters is finding what works for you, there is many opinions and suggestions out there of what to do, use what works for you and scrap the rest.

My approach now a days is keep it simple, the 6 pack salts I listed above does that for me, It took a few rounds to dial it in, to get the ratio's right for my setup/room medium etc. . but that 6 pack will give me everything I need from start to finish, I find it easy and stable as I never have issues with deficiencies or anything. I lean heavily on ratio's within the formula like N to K or K to Ca to Mg etc, depending on plant stage , other people not so much. if I want to play around thats usually with additives, generally I always run fulvic/humic kelp enzymes, microbes, but there is a million more, triacontanol and chitosan are good ones but many more. Have fun

 

[cemchris]

Hey Frankster the best part about growing is there is a million different approaches one can take to grow really good plants, and the only thing that matters is finding what works for you, there is many opinions and suggestions out there of what to do, use what works for you and scrap the rest.

My approach now a days is keep it simple, the 6 pack salts I listed above does that for me, It took a few rounds to dial it in, to get the ratio's right for my setup/room medium etc. . but that 6 pack will give me everything I need from start to finish, I find it easy and stable as I never have issues with deficiencies or anything. I lean heavily on ratio's within the formula like N to K or K to Ca to Mg etc, depending on plant stage , other people not so much. if I want to play around thats usually with additives, generally I always run fulvic/humic kelp enzymes, microbes, but there is a million more, triacontanol and chitosan are good ones but many more. Have fun

Amen. Ratios is everything.

 

[Frankster]

Amen. Ratios is everything.

Yea, i need to quit being a slug and keep logs, and do a bit of statistical analysis, it's a drag, but it's true. You can play around with different techniques, but getting those ratio's down is such a critical component, especially if your doing a week to week program.

Statistics was by far, my least favorite class in college, kinda hard to do when your all smoked up that semester.

Personally, with all of your geniuses at my fingertips, I'm learning more than ever just about various difficiencies look like, that way I'll always know what to look for, at least the more common ones anyhow, and once that kind of stuff becomes routine, the sky's probably the limit. Once your self correcting crap, before it becomes a problem, only little nick picking things to do, much hurrah about minor blemishes and whatnot. That would be the life.