sodium bisulfate vs. muriatic acid for lowering alk

[rck329]

Hey guys,

I want to adjust down the alkalinity of my water change (IO) so that I can do large water changes without spiking alk.

I'd rather not deal with muriatic acid on a regular basis - would sodium bisulfate be considered a safer alternative? Or rather, just that an anhydrous form is safer than liquid?

Thoughts?

Thanks,
Ryan

 

[Randy Holmes-Farley Verified Community Expert]

It is a fine alternative, if you prefer it. The relative effect on pH and alkalinity is the same (lowers both), but it might be easier to handle.

 

[rck329]

Thanks Randy! The additional sulfur would not be of concern, correct? I would be adding 20 grams to 150 L -> 32/120*20 = 5.3g -> 5300 mg/150 L = 35 ppm? Or does the sulfur combine to form something else?

 

[Randy Holmes-Farley Verified Community Expert]

It leaves a small amount of sulfate, which is the third most abundant in in seawater by weight, after sodium and chloride, so the residue is no concern (assuming it is adequately pure).

 

[reeftilldie]

this is exactly what i need to lower my alk in my display, where can i get sodium bisulfite?

 

[rck329]

this is exactly what i need to lower my alk in my display, where can i get sodium bisulfite?

I think you want Sodium Bisulfate, not Bisulfite (both are readily available). Ebay or Amazon carry bulk but I just bought Seachem Acid Buffer since it's not appreciably more costly than bulk. Just be careful dosing your display directly as it will lower ph. Personally, I would just adjust your water change water and then slowly bring your display down with that.

 

[Randy Holmes-Farley Verified Community Expert]

I agree.

 

[reeftilldie]

Hi @Randy
I just mixed new 4 gallons at 5.7 dkh, how much dkh will i get when i do do water change on my 42 gallon at 8.7 dkh? also do u have a formula to calculate this?
Thanks