Does washing soda go bad?

[JimMarshall]

I’m trying to use up a few chemicals that my dad had left over from his hot tub - sodium carbonate, sodium bicarbonate, and sodium bisulfate.
My pH has been low because of the trichlor tablets I’ve been using (store was out of liquid and I could stand some CYA anyways, I was only running around 20 - so I grabbed around 10 3” tablets and have been using them just in my skimmer since my pump runs 24 hours.
Anywho, my pH was down to 7.2, so I added around 1.5 lbs of sodium carbonate figuring that that would bring my pH to 7.8.....

that was an hour, maybe 2 ago, and I am showing no change in the pH.
Can the stuff go bad?

 

[Richard320]

Good question. Let's call @JoyfulNoise

 

[JoyfulNoise]

Unless it gets wet and turns into a block of solid washing soda, then no, it does not go bad.

 

[JimMarshall]

Unless it gets wet and turns into a block of solid washing soda, then no, it does not go bad.

there was some clumping. I essentially had to add water to the container and shake up up and pour it out as a slurry.
My 4 year old and I have been “immersion blending” the pool for a bit, I’ll test again once we get out.

 

[JoyfulNoise]

Yeah, it’s fine. Aside from clumping it really can’t “go bad”. It’s a very stable compound.

 

[Donldson]

Just for the future, highly recommend not doing what you did with the tablets in the skimmer. Took me several 4' hoses before learning that myself, unfortunately.

Out of curiosity, what's your TA sitting at now? Ten 3" tablets is a pretty significant amount of acid to add to your pool.

 

[JimMarshall]

So, in the event that I get out and it still hasn’t shown up, where did it go? Lol

 

[JimMarshall]

Just for the future, highly recommend not doing what you did with the tablets in the skimmer. Took me several 4' hoses before learning that myself, unfortunately.

Out of curiosity, what's your TA sitting at now? Ten 3" tablets is a pretty significant amount of acid to add to your pool.

I didn’t want to buy a floater and assumed that it wouldn’t cause any adverse effect to add to the skimmer as long as my pump was running, which it was.

Ive only added I believe 6 of the tablets so far.
This morning my test results were :


==========================================
Jim's Ahrensville Oasis
------------------------------------------
Build Type: Vinyl
Volume: 13000 gallons
------------------------------------------
Latest Test Result Summary:
FC: 3.0 (5 hours ago)
CC: 0.5 (5 hours ago)
pH: 7.2 (5 hours ago)
TA: 60 (5 hours ago)
CH: 250 (5 hours ago)
CYA: 30 (5 hours ago)
TEMPERATURE: 88° (5 hours ago)
CSI: -0.57 (5 hours ago)
==========================================

 

[JimMarshall]

Ok so it went up to???? 7.4-7.5?



I did see the expected +13 TA


==========================================
Jim's Ahrensville Oasis
------------------------------------------
Build Type: Vinyl
Volume: 13000 gallons
------------------------------------------
Latest Test Result Summary:
FC: 2.5 (17 minutes ago)
CC: 0.0 (17 minutes ago)
pH: 7.5 (17 minutes ago)
TA: 70 (17 minutes ago)
CH: 250 (17 minutes ago)
CYA: 30 (17 minutes ago)
TEMPERATURE: 90° (17 minutes ago)
CSI: -0.19 (17 minutes ago)
==========================================

 

[JimMarshall]

Anyone with any theory of why I didn’t see the pH movement that I was expecting?

 

[JoyfulNoise]

Because pH calculations that large are not exact. Pool water is very complicated mixtures of buffers and salts, pH calculations are not exact. PoolMath additions are only accurate when the pH movements are less than 0.4 units and even that is pushing it.