Never had this happen before - pH seems to be dropping?

[JimMarshall]

Without any intervention from me? Has gone from being in the high 7s to the low 7s (most recently 7.3) without me adding any acid other than CYA (which affects it but it is negligible). My TA is normally high with the fill water here, and as such my pH always drifts UP and I must add MA to drop several times a year.

Also, my pool water tastes icky. I know that its not supposed to be drank, but its inevitable to get some in your mouth.

Latest numbers
FC 6
CC .5
pH7.3
TA 80
CH 300
CYA 50

We've been getting A LOT of rain here... Is it possible that the rain is just very low pH compared to "normal"?

 

[mknauss]

The only way pH lowers in pool water is from a chemical addition or the addition of acidic water.

 

[JimMarshall]

Ok, that is what I was suspecting. Thanks Marty

 

[duraleigh]

How are you chlorinating?

 

[JimMarshall]

How are you chlorinating?

As always, liquid chlorine.

From when I opened until now the only things I have put into the pool have been "Pool Essentials" 10% LC, some Clorox brand CYA granules, and CH flakes

 

[ajw22]

Did you recently add CYA? CYA is mildly acidic and will lower pH some

 

[duraleigh]

That is really puzzling. As marty posts above, pH doesn't go lower unless you add some low-pH chems or acidic water and rainfall can not account for that swing.

If you ever figure it out, patent it quickly because a lot of folks would use it!!

 

[jmikeb]

i would recheck the TA. just to make sure it hasn’t crashed

 

[Rocket J Squirrel]

rainfall can not account for that swing.

OP lives in Oil City, PA. I wonder whether they suffer from acid rain. Seriously.

 

[JimMarshall]

Did you recently add CYA? CYA is mildly acidic and will lower pH some

I have, but not enough to explain that

 

[JimMarshall]

OP lives in Oil City, PA. I wonder whether they suffer from acid rain. Seriously.

Upon doing a little bit of research, we do.

 

[Rocket J Squirrel]

OP lives in Oil City, PA. I wonder whether they suffer from acid rain. Seriously.

Upon doing a little bit of research, we do.

So your next experiment will be to capture some rain water and test its pH.

 

[JamesW]

Is the TA also going down?

How many inches of rain have you received?

Are you getting the water sample from the top of the water where the concentration of rainwater might be higher than the rest of the pool?

 

[JimMarshall]

So your next experiment will be to capture some rain water and test its pH.

Hopefully I'll be able to do that today.

Is the TA also going down?

Actually it's been going up, but I had older testing reagents that I just replaced

How many inches of rain have you received?

Since the pool opened? About 30

Are you getting the water sample from the top of the water where the concentration of rainwater might be higher than the rest of the pool?

I am, hadn't considered that.

 

[JimMarshall]

Looks like the rain is registering at 6.8 ish

the closest gas station with diesel

 

[JimMarshall]

TA has gone from 80 at my last test (4 days ago) to 70 today

FC 0 (eek)
CC 2.5 (double eek)
7.3-7.4?
TA 70
CH 300
CYA 50

 

[JamesW]

Most likely it's just the rain. Monitor closely for a few days to confirm.

Bring the fc up to about 20 and do an OCLT.

 

[JimMarshall]

Most likely it's just the rain. Monitor closely for a few days to confirm.

Bring the fc up to about 20 and do an OCLT.

Put 23 PPM in intending to do just that

 

[JimMarshall]

This morning I was at 19.5 and 1.5 CC - water crystal clear. I might have screwed up and let the chlorine drop for a couple days (life gets in the way sometimes).... but at least whatever it was that I was about to have an outbreak of..... I seem to have been able to "head it off at the pass"

 

[JamesW]

Ok, continue SLAM to completion.