critic acid for FW pH down

[xKEIGOx]

can I use critic acid to lower the pH in freshwater? I can't find sodium biphosphate over here....

 

[randy holmes-farley]

Sorry, I don't know what critic acid refers to. Does it go by any other names?

 

[Chucker]

Randy, I'd think it would be safe to say that "critic" is a typo, and the original poster is referring to "citric" acid.

 

[xKEIGOx]

ops~ yup it's citric.

 

[randy holmes-farley]

Sorry, I didn't think of that.

Sure you could use citric acid, or just acetic acid in vinegar, or even HCl (muriatic acid).

In all of these cases, I'd add it very slowly and monitor the pH as you do it. Commercial products (like phosphates) may be formulated to prevent big drops in pH, while these products will not.

 

[xKEIGOx]

thank you very much!

 

[randy holmes-farley]

You're welcome.

 

[CraigBingman]

can I use critic acid to lower the pH in freshwater? I can't find sodium biphosphate over here....

So I assume that the pH of your freshwater system is higher than you would want it to be. The underlying problem is that you have more carbonate alkalinity in the water than you really want.

Citric acid, acetic acid, and other organic acids will temporarily reduce the pH, but when they are oxidized to carbon dioxide and water... poof, they leave the system and its carbonate alkalinity unchanged.

If you want to lower the system pH, then you need to use something that will knock down carbonate alkalinity. That usually implies using something like NaH2PO4 or NaHSO4. Both are sold as "pH down" agents, and both work. The phosphate based compounds may contribute to algal growth, though.

Craig Bingman

 

[xKEIGOx]

err... NaHSO4 is... ??? :?:

 

[xKEIGOx]

sodium bisulfate?

 

[CraigBingman]

sodium bisulfate?

Yes, sodium bisulfate is a common name for NaHSO4.

Craig Bingman