# Ortho-Phosphoric acid use as Phosphate



## Prajjwal (Sep 18, 2010)

Can Ortho-phosphoric acid be use along with K2SO4 and KNO3....instead of KH2PO4?

If yes then, what should be the amount to be added in a 40lit tank? (O-Phosphoric acid is in concentrated form)


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## Prajjwal (Sep 18, 2010)

someone please share your opinion


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## davemonkey (Mar 29, 2008)

I'm not a chemist, but I think that would be unsafe. Phosphoric acid is not the same as phosphate...I don't think it will behave the way you need it to in making phosphorus available to your plants.

Hopefully some chemists will chime in, but I'm thinking, no.


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## davemonkey (Mar 29, 2008)

Well, I just read a bit about it. I'd almost be tempted to give it a "maybe", but, you need to really know you chemical reactions before you jump into something like this.

http://en.wikipedia.org/wiki/Phosphoric_acid


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## Prajjwal (Sep 18, 2010)

Thanks for the reply...

KH2PO4 + Water= K+, 2H+, PO4--- =K+ and H2O (K+,OH-, H+)= 3H+ will available for acid formation
H3PH4 + Water= 3H+, PO4--- = 3H+ will available for acid formation

I confirmed it from some educational institution that in both the cases PO4--- ions will be available to plants. But I want to know that have anyone ever tried it before? Any practical observation? 

All my quarries raised because Orthophosphoric acid is three times cheaper than Potassium Di-Hydrogen Ortho-phosphate.


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## Skizhx (Oct 12, 2010)

I would suspect that this would be alright to use...

My one concern though would be how much of an impact it would have on your pH to be dosing it in the levels you'd need.

Furthermore, I should state that I do not know enough about chemistry or biology to give you a definitive answer to this, so don't take my opinion and run with it without further confirmation.

My largest concern would be with the effects it might have on your pH though.

You also gotta consider that by dosing this instead, you aren't getting the potassium with the phosphates. So that's going to need to be provided by other means. Sorta gotta wonder if the savings are really worth the trouble?


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