Mixing KNO3, K2PO4 and K2SO4

[donhitme]

Hi all, I'm using the above 3 chemicals for my fert regime. currently mixing with water before dosing.

Anyone knows if it is alright to prepare a large bottle of the fert by pre-mixing all the 3 chemicals (i.e. will it cause a chemical reaction)?

In addition, I am also dosing the lushgro micro, think i can mix this is as well?

thanks

[taz_boy]

base on my A level knowledge in chemistry...i dun think there will be any "hazardous" reaction btw the 3 chemicals.......

any diploma or chemistry major would like to confirm

i always mix phospate and nitrate and dissolve them together b4 dosing them to the tank..so far so good

[donhitme]

hey taz, thanks for the chemicals, my plants starts to bubbles after a couple of hours.
ok, without further ado, i'll prepare a large bottle of the mixed chemicals, save me trouble to mix everytime

[nostalgia]

Hi Donhitme, can share ur proportion of mixes?

[hongrui]

depending on the concentration of your mix, potassium sulphate might precipated out.

potassium sulphate has the smallest solubility product and the combined potassium concentration from KNO3, K2HPO4 and K2SO4 might be just enough to cause the K2SO4 to be 'insoluble'.

no adverse reaction though, as in you won't get a toxic or explosive mixture

[juggler]

Hi all, I'm using the above 3 chemicals for my fert regime. currently mixing with water before dosing.

Anyone knows if it is alright to prepare a large bottle of the fert by pre-mixing all the 3 chemicals (i.e. will it cause a chemical reaction)?

In addition, I am also dosing the lushgro micro, think i can mix this is as well?

thanks

It's OK to prepare a stock solution of all the chemicals provided your tank needs do not change much over time. Or when you just got one tank.

For me with 2 tanks at home, I prepare different stock for my PO4, one for each tank. For K, I dose dry.

Be careful with PO4 and traces. I think someone reported there's precipitation from these 2 compounds, if I remember corectly. But whether affecting nutrient uptake, I am not sure. Sorry - not an expert.

[AquaObsession]

As a beginner with the NO3 and PO4, i prepare them separately. this is because i (we) dose different ppm per week, and i tried so preparation solution concentration of 0.5ppm per ml. Hence i will add different amount of ml of each solution each time, which is not the case if i have a single mix. I then have to make sure the same ml will give me the right ppm per dosage.

also, if i want to up No3 alone, it would be easier.

i am certainly not an expert, just started that last week. so far so good, no algae, plants pearling (but not quite as i wanted) (start slow is good for me until i understand )

[donhitme]

haha, haven't prepare the all-in-one solution yet (suddenly quite bz), will try and let you guys know if they will precipitate or not.
the solution will be for the bi-weekly dose, can always use the remaining chemicals to dose separately.
actually since i dose the other chemicals in approx the same amt each time, i may prepare small bottles of the other chemicals as well

btw, using normal plastic bottles (mineral water) will do right? no need glass bottles hor?

[neon]

The precipitation / cloudy effect when the iron mixed with po4. NPK mixture so far I don't have issue for my 1ft tank mixed solution.

[donhitme]

hey guys, i did the solution and noticed some interesting phenomenons.
Plan for my 50G tank fert solution was to dose 30ml each time:
- 300g of KNO3 in 600ml water
- 30g of K2PO4 in 600ml water
- 240g of K2SO4 in 600ml water

a) while mixing, think my bad planning cause a lot of the chemicals unable to dissolve due to saturation :P
b) the KNO3 solution is COLD!! i can see condensation on the container when mixing (interesting)
c) the K2PO4 solution is somehow COLD too!! and i gives out a mild and unpleasant smell.

anyway I combined all 3 solutions and leaving it to stand, shaking it once a while to try to dissolve more chemicals. the container is still quite cold, and I can see some gas being generated from the solution (dono what gas).

[hongrui]

solubility of K2SO4 is approximately = 12g /100ml (72g/600ml)
solubility of KNO3 is approximately = 36g/100ml (216g/600ml)

since you have already got saturated solutions, shaking won't help to dissolve any more of the solids. and mixing of saturated solutions are not advisable as the resultant mixture will have more solids precipitating out.

[solonavi]

hey guys, i did the solution and noticed some interesting phenomenons.
Plan for my 50G tank fert solution was to dose 30ml each time:
- 300g of KNO3 in 600ml water
- 30g of K2PO4 in 600ml water
- 240g of K2SO4 in 600ml water

a) while mixing, think my bad planning cause a lot of the chemicals unable to dissolve due to saturation :P
b) the KNO3 solution is COLD!! i can see condensation on the container when mixing (interesting)
c) the K2PO4 solution is somehow COLD too!! and i gives out a mild and unpleasant smell.

anyway I combined all 3 solutions and leaving it to stand, shaking it once a while to try to dissolve more chemicals. the container is still quite cold, and I can see some gas being generated from the solution (dono what gas).

Hi Bro, suggest u download the Chuck fert calculator. It will let u know if the amount of chemical and water mixture is not gona dissolve fully.

http://www.csd.net/~cgadd/aqua/art_plant_aquacalc.htm

Cheers
JC

[donhitme]

solubility of K2SO4 is approximately = 12g /100ml (72g/600ml)
solubility of KNO3 is approximately = 36g/100ml (216g/600ml)

since you have already got saturated solutions, shaking won't help to dissolve any more of the solids. and mixing of saturated solutions are not advisable as the resultant mixture will have more solids precipitating out.

wow, this is great info. With this, I'll go increase the water appropriately and that will means I dose more ml lor , main thing is to get them dissolve, haha.

solonavi, thanks for the link. I used that previously when dosing directly to tank, didn't check when mixing this solution.

[Ibn]

It's possible to premix decent size batches; I mix 10 day supplies of NPK w/out any problems with precipitation.

[ah^siao]

i noticed that if u mix them u'll get condensation outside the botles too

[donhitme]

yup, that's what happened

[juggler]

yup, that's what happened

Reaction between KNO3 and water is endothermic. I enjoy demonstrating that effect to my kids.
I think same goes for KCl too ("Low-Salt" - can buy from NTUC).

[solonavi]

A funny thing happen yesterday. As mentioned, I have mixed a solution of KNO3, KH2PO4 and traces(ferropol) and left it standing. To my surprise, I found something in the bottle and its no preciptitation. Its a LIZARD! Yes the 4 legged creature that climb walls.

JC

[donhitme]

U win already liao lor :P