Borax vs washing soda- which is better and cheaper?

[PoolsideinLA]

My ph is 7.2 and I need to bring it up. Is there any difference between adding the washing soda vs the borax?

I've priced both and the soda seems cheaper, although I just bought borax in bulk on Amazon Prime Pantry for much cheaper than in store (a handy little service if you've never used it).

Is it just a matter of preference or does one do the trick better than the other?

 

[Richard320]

You might not need either. What's the TA reading? It might just need some aeration to drive pH up. And actually, 7.2 is a perfectly acceptable number, so there's no reason to do anything with it at all.

Now... for your question. Head over to poolmath and scroll down to the bottom and look at Effects of Adding Chemicals. You will see how much each pH adjuster will affect the TA. You might pick one over the other because of that. Or because you can find one in the store but not the other.

 

[JasonLion]

Borax doesn't raise the TA as much, which is sometimes valuable. However, if you are dealing with trichlor tablets, washing soda is better as it comes closer to balancing out the PH/TA effects of trichlor tablets.