where to find phosphoric acid?

[vss]

Hi I'm asking on behalf of a friend. He wants to get phosphoric acid to adjust the pH but don't know where to buy it. I could not find it at those aquatic stores either. If anybody has any hint could you please let me know? Thanks a lot！

Xiaofei :)

[Inland Empire Discus]

To my knowledge you can only get it from chemical companies and it is strictly regulated ( in CA anyway) as it is a hazardous material. The smallest quantity I can buy at a time is 4 gallons.

[ref0716]

I've alwasy used Hydrochloric (AKA Muriatic) acid. Available in masonry supply outlets - it is used to clean and etch cement. A gallon costs about $7.00 or so and will last a VERY long time. But be careful. This stuff is strong. I dilute three to one with water, and a capful of this stock will drop the pH in 20 gallons from 7 to 6. Remenber to always add acid to water, not the other way 'round. HTH
Richard

[John_Nicholson]

Why is he adjusting his Ph? Unless he has a really good reason he is just making his life difficult.

-john

[roundfishross]

you can get 85% phosphoric acid from duda diesel on ebay or via thier website jt runs about $30 for a quart


Leo

[daveo]

Using this stuff in the past I found that the PH jumps back to where it was in hard water.
Spikes are not a good thing.

Daveo

[Latro]

I've alwasy used Hydrochloric (AKA Muriatic) acid. Available in masonry supply outlets - it is used to clean and etch cement. A gallon costs about $7.00 or so and will last a VERY long time. But be careful. This stuff is strong. I dilute three to one with water, and a capful of this stock will drop the pH in 20 gallons from 7 to 6. Remenber to always add acid to water, not the other way 'round. HTH
Richard
Coming from the standpoint of a chemist, this is a TERRIBLE idea if you want your pH to be stable. This will do very little (a few tenths of a unit) until you've nearly wiped out your buffer capacity, and then your pH will begin to plummet rapidly at even very small additions, at which point you will have no buffer capacity in either direction and your pH will probably oscillate wildly. Even by the time you've dropped the pH by a unit you've increased HA/A by a factor of 10, which means you now have maybe 20% of the buffering capacity you had before (assuming you were at 50/50 before you're now at about 90/10).

Phosphoric acid is a much more reasonable (albeit still ultimately not a good idea for various reasons) solution, because it actually creates a buffer system of its own, distinct from the bicarbonate buffer system, and with its equilibrium level being at a lower pH than a bicarbonate buffer system (which is what an aquarium would usually have).

[kaceyo]

Muriatic acid has been used by aquarists for a long time. Whether or not it's a good idea I'll leave for others to discus, but with daily wc's and some preliminary preperation and research it can be used successfully.

[Latro]

Muriatic acid has been used by aquarists for a long time. Whether or not it's a good idea I'll leave for others to discus, but with daily wc's and some preliminary preperation and research it can be used successfully.
With daily water changes it's pretty much a moot point, yes; you're not getting much nitrification in between water changes and are putting a little more buffering capacity back in at each one, so you never get very very low buffering capacity (assuming you're, say, dropping the pH of your input water by one unit with HCl). With less frequent water changes you'll definitely exhaust your buffering capacity, though.

[kaceyo]

Agreed.