How Much 45% Phosphoric Acid is Needed to Raise PO4 by 1ppm in 1 Litre of Water?

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To raise phosphate (PO4) levels by 1 ppm in 1 liter of water using 45% phosphoric acid, calculations indicate that approximately 0.67 ml is needed. This is based on the understanding that 1 ppm corresponds to 1/1000 ml, and adjustments are made for the concentration of the acid. For larger volumes, such as a 300-liter tank, the amount required would be proportionately higher, but the calculations initially suggested a miscalculation of 7.2 ml instead of the correct 0.67 ml. It is emphasized that the phosphoric acid should be added slowly to avoid high local concentrations that could harm fish. Additionally, comparisons are made to the phosphoric acid content in common beverages, highlighting the importance of careful measurement and administration when dealing with aquatic environments.
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How much 45% phosphoric acid (in ml) would it take to raise PO4 by 1ppm in 1 litre of water?

I need to be sure as fish are involved. It will be administered over a 24 hour period.
 
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Without a lot of thinking (maybe):

1 ppm of phosphoric acid (measured as a fluid in mls) in a liter would be 1/1000 mls.
45% phosphoric acid would require 1/45 x 1/1000 mls.
Figure out the fraction of the PO4 in the phosphoric acid by its molecular weight.
Multiply by that number to get your result.
 
Thanks,

I calculate that at about 7.2ml of 45% phosphoric acid to raise PO4 by 1ppm in 300 litres.
 
Add slowly or high local concentrations may cause problems before it is mixed throughout the whole volume.
 
skyshrimp said:
I calculate that at about 7.2ml of 45% phosphoric acid to raise PO4 by 1ppm in 300 litres
Are you sure seems high to me?
 
gleem said:
Are you sure seems high to me?
That's was my first thought, but
skyshrimp said:
in 300 litres.
so 300x of a liter's worth.
 
my method is conc1 x vol1 = conc2 x vol2
 
Let’s say you had it at 100% then 1ml would be enough for 1M ml =1000liters
Therefore at 45% 1 ml would be enough for 450 liters
You have 300 liters, so 2/3 of that.
Solution:
Get a cup of water add 1ml and mix
Drop 1/3 of a cup of the mix
Add the remaining mix to your water. Problem solved!
You need .67 ml of it but that’s harder to calculate
 
  • #10
Thanks,

I made a mistake with my rough calculation. I should have estimated 0.72ml, not 7.2ml. 0.67ml is more accurate. I was adding slowly and testing each day. I got to 1ppm quickly, so knew my math was off.
 
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  • #11
Also, there is 60mg of phosphoric acid in a can of Cola-Cola.

One drop of liquid is 0.05ml which is 50mg. My phosphoric acid is 45%, so I figure I can add 2 drops to a 330ml drink to safely give it some extra bite.
 
  • #12
skyshrimp said:
I need to be sure as fish are involved.
skyshrimp said:
Also, there is 60mg of phosphoric acid in a can of Cola-Cola.

One drop of liquid is 0.05ml which is 50mg. My phosphoric acid is 45%, so I figure I can add 2 drops to a 330ml drink to safely give it some extra bite.
Wait, you've gone from a 300 liter fish tank to a can of soda? I'm getting dizzy... o0)
 
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