Baking Soda vs Soda Ash

[tanstaafl2]

Keep reading in various places differing opinions about Sodium Bicarb (baking soda) and Sodium Carbonate (soda ash).

Some places say don't use baking soda, use only soda ash. Others seem to have no problem with Bicarb.

Is there a big difference in terms of use in a spa?

[orlandoguy]

My pool supply store says yes, there is a big difference and he probably makes more money saying that. But baking soda works fine for me.  Either way, both are cheap.  Baking soda much more so.

[Brewman]

Most of the alk increase products I've looked at contain 100% sodium bicarbonate.  Baking soda.
That include the ones packaged and sold at pool and spa dealers, the bigger cheaper containers sold in the pool section of the big boxes.

[HotTubMan]

Bicarbonate will raise TA more than pH.

Ash will raise pH more than it will TA.

So, if you have low TA and good pH, use bicarbonate.

If you have low pH and good TA, use ash.

[Tatooed_Lady]

Bicarbonate will raise TA more than pH.

Ash will raise pH more than it will TA.

So, if you have low TA and good pH, use bicarbonate.

If you have low pH and good TA, use ash.

I'm gonna start taking notes....

[luvin_tubin_sqezin]

I'm gonna start taking notes....

I swear, I've already started printing out some of these posts for future reference....and I don't even have my tub yet!!!!  

[tony]

Bicarbonate will raise TA more than pH.

Ash will raise pH more than it will TA.

So, if you have low TA and good pH, use bicarbonate.

If you have low pH and good TA, use ash.

And if you have low TA and low pH, use bicarbonate.

FWIW, I have only used baking soda.

[tanstaafl2]

Bicarbonate will raise TA more than pH.

Ash will raise pH more than it will TA.

So, if you have low TA and good pH, use bicarbonate.

If you have low pH and good TA, use ash.

Excellent. Very helpful to know. Probably should have used soda ash then as TA was OK towards higher range and I was most interested in raising the pH.

Live and Learn!

[HotTubMan]

And if you have low TA and low pH, use bicarbonate.

FWIW, I have only used baking soda.

Good point and most will if they follow this rule:

Always adjust TA then pH.

[Tman122]

I exclusivly use baking soda. Water comes from the tap 60-70 TA and 7.0 PH (acid rain in Minnesota I spose) Baking soda does exactly what I need it to do to both.

[hottubdan]

There will be a test tomorrow.  Bring your number 2 pencil.

[Dr. Spa™ Ret.]

Sodium bicarbonate (sodium bicarb, bicarb or baking soda) has a pH of 8.3 and contributes bicarbonate to total alkalinity. Because the spa water pH is close to the pH of the bicarb, it will have a greater effect on TA than pH. So if you want to raise just the alkalinity with a small rise in pH, use bicarb. 1 lb of bicarb added to 10,000 gallons of water will increase TA by 7.15 ppm and increase pH by about .1 to .2 unit.

Sodium carbonate (soda ash) has a pH of 13.0 and contributes carbonate to total alkalinity. Because it has a high pH, soda ash will raise both pH and total alkalinity. 1 lb of soda ash added to 10,000 gallons of water will increase TA by 11.33 ppm and will increase the pH by about 1.0 unit.

[Tatooed_Lady]

There will be a test tomorrow.  Bring your number 2 pencil.

*LOL* I'd fail......miserably.....but then, so long as I keep track of how much of what does what to what (in writing, no less), I should be ok.....  
My husband is gonna kill me when he finds that post-it note on his forehead.......

[tanstaafl2]

So how do I raise pH and hopefully have the least affect on TA if both Bicarb and Soda Ash raise TA. I guess to get the most bang for pH compared to TA I should have used Soda Ash instead of the Bicarb as was suggested earlier.

Live and Learn I suppose. Doesn't seem I did too much harm with Bicarb so far. Not sure pH is raised that much but TA still seems to be OK albeit on the high side at 120ish.

[Snowbird]

Keep reading in various places differing opinions about Sodium Bicarb (baking soda) and Sodium Carbonate (soda ash).

Some places say don't use baking soda, use only soda ash. Others seem to have no problem with Bicarb.

Is there a big difference in terms of use in a spa?

Try this thread.
http://www.whatsthebest-hottub.com/cgi-bin/yabb/YaBB.pl?board=wtb-hottub;action=display;num=1140625398;start=10