Dosing Sodium Hydoxide

[JasonCox]

I just want to get my ph up from 7.9 to 8.3 can I just dose sodium hydroxide (lye) to do this as long as I watch my alkalinity, calcium, and magnesium and keep them in the correct parameters. I’ve been dosing Kalk for about a month and my ph goes up but then drops right back off. I’ve noticed with only 1 tablespoon of lye to a gallon of Rodi water my ph has risen and holding around 8 where before it would raise with Kalk and then just drop back to 7.8 after a few minutes. I don’t really want to mix a bunch of chemicals together and would rather dose anything else I may need separately. I feel as I have more control that way. Do you have any other advice? Thank you
P.s. I run a recirculating co scrubber and have a refugium with chaeto

 

[Randy Holmes-Farley Verified Community Expert]

You can use sodium hydroxide as a high pH alk supplement. I give recipes for it as a diy two part.

How much impact you can have on pH without alk getting too high will depend on the nature of the tank system.

 

[Randy Holmes-Farley Verified Community Expert]

That said, the pH rise from sodium hydroxide and calcium hydroxide (kalkwasser) is identical per unit of alk (hydroxide) added.

 

[JasonCox]

That said, the pH rise from sodium hydroxide and calcium hydroxide (kalkwasser) is identical per unit of alk (hydroxide) added.

So should I add more that a tablespoon to a gallon of water ph was reading around 14 in mixture. Will it go higher with more lye or is 14 about as high as it goes. I’m assuming if I add more lye it will also increase the alk. Thanks Randy

 

[Randy Holmes-Farley Verified Community Expert]

So should I add more that a tablespoon to a gallon of water ph was reading around 14 in mixture. Will it go higher with more lye or is 14 about as high as it goes. I’m assuming if I add more lye it will also increase the alk. Thanks Randy

I know it may seen counter-intuitive, but the pH in the dosing container is largely irrelevant to the effect it has on the tank. One can add a solution at 7.0 (pure fresh water) and it will raise the pH of seawater at pH 8.0.

Both the pH and alk effects exactly increase as the amount of hydroxide dosed increases, whether that is by usign the same dosing volume at higher potency, or a higher volume at the same potency. In general, the exact concentration doesn't matter, only the total amount of hydroxide added.

My recommendation is to make this DIY two part for several reasons, including that you can use a dosing calculator for the alk effect:

https://www.reef2reef.com/threads/second-new-diy-two-part-recipe-with-higher-ph-boost.357080/

 

[Troylee]

I’m going this route as I’m fighting low ph myself.. I’ve tried everything and thought excess co2 was my problem because I burned through media in a co2 scrubber in just a couple days, my ph still was only 8.1…… I finally broke down and punched a hole in my wall and have my skimmer pulling from outside and I’m still running 7.75-8.01 ugh…. With that being said I ordered this, is this safe Randy? It says meets food grade standards.

 

[Randy Holmes-Farley Verified Community Expert]

It may be fine, but I recommend food grade sodium hydroxide. it is inexpensive and carries a purity assurance.

Amazon product ASIN B0875LR274

 

[Justdrew]

I’m going this route as I’m fighting low ph myself.. I’ve tried everything and thought excess co2 was my problem because I burned through media in a co2 scrubber in just a couple days, my ph still was only 8.1…… I finally broke down and punched a hole in my wall and have my skimmer pulling from outside and I’m still running 7.75-8.01 ugh…. With that being said I ordered this, is this safe Randy? It says meets food grade standards.

That's the same one I have been using for about 6 months now.