Never has this happened

[Cowfd13]

13,000gal, above ground, 76 degree water

just opened yesterday
I tested the pool with the TF-100

CH - 0
PH - below 6.8
TA - goes to red immediately w/R-0008, not green
CYA - 90
Borates - can’t check. Test strips must be bad, everything tests 90-100, even a Poland spring bottle

I have NEVER in 8 years seen a PH below 6.8, our fill water is 6.9. I had to add about 18” of water after removing the cover to start filter.
So far, I’ve added 1lb of 73% cal-hypo and one box of Borax (70oz)

new test:
CH - 10
PH - still under 6.8
TA - still untestable

Help??
What would cause this major anomaly and where would you start?

 

[Texas Splash]

You need to get the TA up ASAP. For whatever reason it crashed taking the pH with it. Very corrosive. Use enough baking soda to increase the TA in increments of about 30 ppm at a time, let mix for about 30 min and re-test and add as necessary to get your TA up to about 60-70. Also try to aerate as much as possible to help the pH rise. Keep us posted.

 

[Texas Splash]

By the way, have you been using pucks? That CYA is really high?

 

[Donldson]

I heartily second Pat: get that TA up quickly.

Did you happen to put some sort of chlorine floater in the water over the winter? Opening to no TA and a CYA of 90 is somewhat rare as typically the opening and closing process gets some fresh water which lowers the CYA and raises the TA. Having trichlor pucks in the water over the winter would be one possible explanation.

 

[Cowfd13]

Pucks were only used during 2 week long vacations last summer. Nothing during winter. Dumping baking soda now. I’ll update

 

[Cowfd13]

You need to get the TA up ASAP. For whatever reason it crashed taking the pH with it. Very corrosive. Use enough baking soda to increase the TA in increments of about 30 ppm at a time, let mix for about 30 min and re-test and add as necessary to get your TA up to about 60-70. Also try to aerate as much as possible to help the pH rise. Keep us posted.

Ok I dumped baking soda and waited - retested and got 30. Dumped more for now, but I think I need to consider dumping soda ash on the next go, so I can bring up the PH at the same time

any thoughts on how this happened??

 

[Texas Splash]

any thoughts on how this happened??

Anything at this point is just speculation. Something acidic would've been the #1 assumption. Aside from that, I'm not sure what chemical process might have occurred over the winter. It's good you are seeing some rise in the TA. I would follow-up to ensure you get it well into the 60-70 range. Even if you over-shoot a bit it won't hurt. Then monitor the pH a bit before adding anything else. With the TA and aeration, you might find the pH rise on its own.

 

[Donldson]

Your pH is already going up with the TA, test both pH and TA on your next test and if your pH is still low then very carefully and conservatively dose soda ash. Undershoot whatever you think you want to hit because there's a good chance you will see a higher rise than PoolMath will calculate. You can always add more, but having to add acid after all this would be painful.

How did it happen is a good question. Did you test your water before closing? It's really odd because one way TA could drop is if a bunch of rainwater got in, but if that happened your CYA would also have been zero. If your CYA is about what it was when you closed then your TA should be too, unless something acidic was added between your final test and first test.

 

[Cowfd13]

Your pH is already going up with the TA, test both pH and TA on your next test and if your pH is still low then very carefully and conservatively dose soda ash. Undershoot whatever you think you want to hit because there's a good chance you will see a higher rise than PoolMath will calculate. You can always add more, but having to add acid after all this would be painful.

How did it happen is a good question. Did you test your water before closing? It's really odd because one way TA could drop is if a bunch of rainwater got in, but if that happened your CYA would also have been zero. If your CYA is about what it was when you closed then your TA should be too, unless something acidic was added between your final test and first test.

I did not test immediately before closing, because it was tested 3 days earlier. We swam in it. I actually decided last minute due to incoming weather, to close it then - instead of 2 weeks later as planned. My last test was:

CH - 3
PH - 7.2
TA - 65
Borates - 35
CYA - 60

none of it makes sense. We gained no water - we actually dumped 12”, then lost 6” between hot fall days and a slightly late opening. Although my pool is in the 70s now, the top 6” were 94 when I opened it.

 

[Flying Tivo]

Have you checked your Reagents exp date?

 

[Cowfd13]

Have you checked your Reagents exp date?

They’re all new. Got my refill kit and only used new

 

[Cowfd13]

Your pH is already going up with the TA, test both pH and TA on your next test and if your pH is still low then very carefully and conservatively dose soda ash.

I did retest PH when I tested the TA and got 30, it was still below test kit level (under 6.8)
I’ll retest in a few mins and update

 

[Cowfd13]

Update - I’m at TA 40, dropped more baking soda

the PH - still below 6.8, but color is getting closer to 6.8. It’s not so pale anymore

 

[Texas Splash]

Progress is good. Keep going in stages.

 

[Cowfd13]

Progress is good. Keep going in stages.

I’m at TA - 70, PH looks 6.8 now

 

[Texas Splash]

Nice. Continue the aerating. Aerating would be idea to lift the pH. If the pH doesn't creep up to 7.2 by tomorrow morning, consider adding a little baking soda to get the TA up to 80.

 

[JamesW]

I did not test immediately before closing, because it was tested 3 days earlier. We swam in it. I actually decided last minute due to incoming weather, to close it then - instead of 2 weeks later as planned. My last test was:

CH - 3
PH - 7.2
TA - 65
Borates - 35
CYA - 60

What was added after this test?

The only way that the TA could go to zero is if 1.5 gallons of acid were added.

Maybe someone added acid and they thought it was liquid chlorine?

 

[Cowfd13]

What was added after this test?

The only way that the TA could go to zero is if 1.5 gallons of acid were added.

Maybe someone added acid and they thought it was liquid chlorine?

Literally nothing. And no one touches the pool chems but me. I don’t even have acid on the premises, because I’ve never needed it.

 

[JamesW]

TA does not just disappear.

Either the test was wrong or acid was added.

 

[Cowfd13]

TA does not just disappear.

Either the test was wrong or acid was added.

Multiple tests were not wrong. I have no idea how acid could’ve entered my pool over the winter while it was covered and locked. It’s ridiculous to think someone snuck on my property to sabotage it, and I literally don’t have acid. 8 years I’ve never needed it - and I didn’t want it on the property unless I did.

either way, currently I have TA - 70, and PH 7.2

it took almost 12lbs (there’s about a pound left in the bag, so 11 was used) of baking soda to correct it.

oh, and now that those have leveled off, my CYA is registering at 30. So the ph or TA being so low, must have affected the CYA test.