Sodium Bicarbonate versus Soda Ash

[stevea295]

Well our nightmare pool remodel continues.Remodel was started the first week of June and we still haven't had a swim yet.
During the plastering process, the PB did not mix the dye in the hopper long enough and we got dark blue color streaks in the finish.The finish we chose was Luna Quartz by Wet Edge. The PB attempted to "burn" the color streaks out with gallons and gallons of muriatic acid. Well, needless to say it did not help. Yesterday, the PB sent out an employee to "neutralize" the acid that was put in 3 days ago. He added 20 #s of Sodium Bicarbonate to the pool. I just tested the pH and I am still in the 6.5 -6.8 range,TA was 50.
I thought that Sodium Bicarbonate was to raise the Alkalinity and that Soda Ash is to raise the pH. Am I wrong???

 

[257WbyMag]

Sodium bicarbonate is used mainly to raise TA. It has a negligible effect on pH, but its main effect is on TA. Soda ash raises both TA and pH quite well.

If he added lots of acid as you say, it may take more than you have added to raise that TA and pH. Are you aerating too?

 

[stevea295]

Yes,the best attempt at aeration is to point the pool returns up towards the surface. I just don't see how after putting in 12 gallons of muriatic acid in a 19,000 gallon pool, Sodium bicarbonate is going to do the job of bringing up the pH in a timely fashion instead of soda ash. I also removed all the hose and zodiac cleaner until the pH is in an appropriate range. The sad part is that the PB admitted that the only way to fix the finish is to jackhammer it all out and start again.

 

[JasonLion]

When raising the PH from really really low it is best to use Borax, fine to use soda ash/washing soda/PH Up, and only so so to use sodium bicarbonate/baking soda. Sodium bicarbonate will raise the TA way too much by the time the PH comes up to where you want it.

Sodium bicarbonate raises both PH and TA. When the PH is really really low sodium bicarbonate raises the PH a fair bit, but as the PH starts to come up it starts raising the PH less and less. By the time you are in the normal PH range for a swimming pool the effect on PH is so small that you can usually ignore it.

12 gallons of muriatic acid is going to have removed a noticeable amount of plaster. That will have shortened the lifetime of your plaster and also raised the CH level noticeably.

 

[stevea295]

Thank you for confirming what I thought. I could not believe that that Sodium bicarbonate would do what the PB said it would. Like I mentioned above, the whole plaster job has turned into a debacle and next week I have a meeting with the VP of the company. The pool is getting re-plastered as far as I am concerned.In the meantime I have to balance the water to prevent corrosion to anything else in the pool.