Making washing soda

truber

Member
Jul 17, 2020
5
Baden, Ontario
Has anyone here tried making washing soda from baking soda? My local feed mill sells baking soda in 25kg bags at $20 for cattle feed, and I know baking it at 400F for an hour decomposes baking soda into washing soda.

If I'm doing the math right, this would work out to about $1.30/kg of washing soda (not counting the gas to run the oven), which is almost a third of what I've been able to find it for elsewhere. Anyone else tried this in bulk?

Btw, our pool is shadowed by pine trees, we get a lot of needles, which I think is why my pH keeps falling.
 

JamesW

TFP Expert
Mar 2, 2011
20,360
It's not a good idea. Just add baking soda to the pool directly and the pH will rise. If the pH is constantly going too low, the TA is too low.

Are you using tabs?

What are all of the readings?
 

truber

Member
Jul 17, 2020
5
Baden, Ontario
No, previous owner used trichlor tabs until CYA was high, and I'm waiting for K2006C to arrive before I dump water. I'm using 12% chlorine.

readings this morning:
FC: 3
pH: 7.2
TA: 100
CYA: 100
T: 28C/82F

The CYA reading is from a test strip, since my kit now only does the first 3.
 

Mdragger88

Bronze Supporter
Jun 1, 2018
1,167
Hernando, Ms
is it possible to make soda ash in your oven- yes. Is it advisable on a large scale. Not really. I have done it to make a small batch of laundry soap in a pinch but churning out the amounts needed for pool additions would gregarious.
If you’re on a liquid chlorine diet now you likely won’t have a need for washing soda in bulk. I haven’t added any to my pool for over 5 years since I stopped feeding it acidic trichlor....
Your ta is fine - your ph is fine & will rise with aeration like Jim said.
That fc is way low. Until u do a drain u need to at least target 11 fc daily see FC/CYA Chart
 

truber

Member
Jul 17, 2020
5
Baden, Ontario
Yep, I've been aiming for 12 FC but wanted to raise the pH before adding more. It's hard to measure FC above 5 with my kit since I have to dilute. :(

I didn't realize washing soda would raise my TA too, so thanks for the suggestion to aerate. I have 3 jets, one shallow end, one deep end, and one wide spray on the stairs. I pointed the two in the shallow end up, especially the stair sprayer seems to do a lot.
 

borjis

LifeTime Supporter
Aug 19, 2014
3,285
Pacific NW
You can use 20 mule team borax instead of washing soda to raise pH. Little to no effect on TA.

I tried turning baking soda into washing soda. Followed direction but it didn't work. It acted like baking soda.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,923
San Dimas, CA (LA County)
Constantly falling pine
No, previous owner used trichlor tabs until CYA was high, and I'm waiting for K2006C to arrive before I dump water. I'm using 12% chlorine.

readings this morning:
FC: 3
pH: 7.2
TA: 100
CYA: 100
T: 28C/82F

The CYA reading is from a test strip, since my kit now only does the first 3.
I see high CYA and low FC and a big maybe on CH. The pH and TA are acceptable, so leave them alone and go swimming.

Even though low CH is no problem for a vinyl pool, high CH levels can still contribute to scale formation, so you ought to know what yours is. It will also tell you if Cal-hypo could be a chlorination option should bleach get scarce.
 
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JimMarshall

Gold Supporter
TFP Guide
Jun 5, 2017
1,003
Oil City PA
You can use 20 mule team borax instead of washing soda to raise pH. Little to no effect on TA.

I tried turning baking soda into washing soda. Followed direction but it didn't work. It acted like baking soda.
The borax still raises the TA, just only about half as much as washing soda.
Too much TA and he will just be chasing his pH back down with acid.
Aeration is best. OP, pointing your fan jet up as you described should work perfectly!
 
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JamesW

TFP Expert
Mar 2, 2011
20,360
With that TA and only using liquid chlorine, it doesn’t make sense that the pH would go down. So, something else is going on. The CYA is probably way higher than 100.
 

truber

Member
Jul 17, 2020
5
Baden, Ontario
Even though low CH is no problem for a vinyl pool, high CH levels can still contribute to scale formation, so you ought to know what yours is. It will also tell you if Cal-hypo could be a chlorination option should bleach get scarce.
I have some expired-last-year strips from last owner that include hardness, and they read in the 0-250 range (all the colours look the same to me until 500). I've seen no signs of chlorine shortage around here though. Pool store is still selling 12% in bulk 10L jugs.

With that TA and only using liquid chlorine, it doesn’t make sense that the pH would go down. So, something else is going on. The CYA is probably way higher than 100.
I tried diluting 3:1 and using a test strip and it looks between 0 and 30-50. 🤷‍♂️ Could be? Still waiting for my test kit to ship...