Help with pH

[kdoonan]

Up until last week I've had beautifully clear water. The pH was a little low at 6.5 and that calculator kept telling me to add Borax. I hadn't had time to get to the store. I finally did last week and I put in 1/2 of what the calculator said. Within two days my clear pool was cloudy and my pH was suddenly high. I got nervous and pulled the chlorine up to 14 just to be sure there wasn't any algae forming. When the chlorine didn't change the cloudiness I researched pH and it said high pH could cause the cloudiness. I've now got the pH back down to 6.5 and the pool is clearing but the calculator is still telling me to add Borax. Obviously I dont' want to do that, as it seems my pool likes a lower pH.

Here are my questions.
Will my pool eventually clear? Am I missing something? It's getting better but it's still not great.
If it's clear is a 6.5 pH okay?
Why did this happen? Was there something I wasn't measuring?

Here are my numbers. I use the TFP Kit and the BBB method. In three years this is the first blip in pool clarity.
FC 6
pH 6.8
CYA 50
TA 120

These numbers are pretty consistent with what they were before I raised the pH and the cloudiness arrived.
Thanks a bunch!

 

[simland]

How are you measuring a pH of 6.5/6.8?

7.5 is good and 7.8 is at the very top of what you should have.

 

[frogabog]

6.5 pH is not good at all. Your water is acidic now. You absolutely need to raise the pH right away to at least 7.2. However, your TA is high so you'll need to aerate to raise the pH. Do you have any water features that you can turn on to create bubbles?

Did you read that high pH causes cloudiness here? That's a new one for me...

I think you should go back to Pool School so that you understand how to raise pH and lower TA. Also, your test results are incomplete. What are the TC and subsequent CC results?

According to the results you did give, you do not need to use borax to raise ph and should not. Every time you use borax, you'll raise TA. You need to lower TA (closer to 60-70ppm) and you do that with muriatic acid. But muriatic acid lowers pH. So, you do a little acid, aerate to raise pH, and then do a little acid again. It's a process, it takes time, but once you get your TA in line your pH will be far more stable.

 

[kdoonan]

How are you measuring a pH of 6.5/6.8?

7.5 is good and 7.8 is at the very top of what you should have.

I used the kit that came in the TFP test kit. It's blue, I forget the name of it.

 

[kdoonan]

6.5 pH is not good at all. Your water is acidic now. You absolutely need to raise the pH right away to at least 7.2. However, your TA is high so you'll need to aerate to raise the pH. Do you have any water features that you can turn on to create bubbles?

Did you read that high pH causes cloudiness here? That's a new one for me...

****I don't remember where I saw it. I think I just googled high pH.

I think you should go back to Pool School so that you understand how to raise pH and lower TA. Also, your test results are incomplete. What are the TC and subsequent CC results?

*****FC was 5 and CC was 1 for a TC of 6

According to the results you did give, you do not need to use borax to raise ph and should not. Every time you use borax, you'll raise TA. You need to lower TA (closer to 60-70ppm) and you do that with muriatic acid. But muriatic acid lowers pH. So, you do a little acid, aerate to raise pH, and then do a little acid again. It's a process, it takes time, but once you get your TA in line your pH will be far more stable.

*****Thank you for this. I didn't realize my TA was too high. I'll work on aeration. I've never had to do that before.

 

[frogabog]

Ahhh... your combined chlorine is 1ppm. Time to begin shocking again my friend. Your pool isn't clearing because it's not finished with shocking. It most certainly has absolutely nothing to do with pH (low, or high).

Remember, you're not done shocking till you meet all three criteria:

1- .5ppm or less combined chlorine (CC)
2- Overnight Chlorine Loss Test (OCLT) shows less than 1ppm loss
3- Water is clear

Water is clear is the hardest one to get past because it actually can take a while to filter out all the dead algae. It seems odd to continue maintaining shock level when it's almost clear, however it's essential. We're not looking for invisible clear could read the fine print at the bottom clear... but it should be clear enough so that there's no doubt that it's not unclear. (hmmm... gobbly goop I know, lemme try again...)

There should be no reasonable doubt that the water is clear. If in doubt at all, it's not clear.

This time, raise to shock level and test hourly at first, add bleach to get back to shock level. Keep that up till you can increase the time between dosings because you're not losing as much chlorine per hour. Then do two hours, and so on.

Keep filtering 24/7 as well.

 

[kdoonan]

Wow Frogabog, your information is hugely helpful. I read through pool school 3 years ago and clearly need a refresh. This is the first problem I've had so I didn't realize the impact of CC. When I was doing the test I wondered why the water was cloudy still after it changed from pink. Time for a reread.

Today is going to be a hot and humid day with temps near 95. I put a some chlorine in last night because we are having a hot streak and the kids were in all day yesterday. Today is going to be another scorcher. They've been swimming in the pool like this all week so my sense is, what's one more day? We are out all day tomorrow and Monday so I can shock the heck out of it.

One last question, if you don't mind. Should I deal with the TA at this time too? I revisited all the numbers and it's still telling me to put more Borax in however another poster mentioned that will just raise the TA more. I'm totally confused on this one. I took a snapshot of the pool calculator results in the event it's helpful.

 

[duraleigh]

I used the kit that came in the TFP test kit. It's blue, I forget the name of it.

It's a K-1000 and it will only test down to 6.8....still don't know how you got 6.5.

Disregard your TA for now and get your pH up to 7.2 - 7.6 sooner rather than later.

 

[kdoonan]

I used the kit that came in the TFP test kit. It's blue, I forget the name of it.

It's a K-1000 and it will only test down to 6.8....still don't know how you got 6.5.

Disregard your TA for now and get your pH up to 7.2 - 7.6 sooner rather than later.

Thank you Dave! It was the K-1000 and my eyes are bad so probably misread the number.

 

[simland]

I used the kit that came in the TFP test kit. It's blue, I forget the name of it.

It's a K-1000 and it will only test down to 6.8....still don't know how you got 6.5.

Disregard your TA for now and get your pH up to 7.2 - 7.6 sooner rather than later.

Thank you Dave! It was the K-1000 and my eyes are bad so probably misread the number.

That's kind of what I was wondering about because I don't know a kit that lets you go down to 6.5 unless you do some reverse math with base demand.

I would listen to Frogabog. Good advice. If your pH truly is that low, then the advice is perfect.

1) Aerate
2) Add a lot of bleach.

 

[kdoonan]

Pool looks much better today! I pulled the chlorine up to 24 last night and today it's at 20 with cc at .5. (Recommended shock level was 20) The pH has been jumping around though, yesterday it said it was 6.8 and today it's back up to 7.6. We spent a lot of time splashing in the pool yesterday and I turned the jets up for aeration. My sense is to stay the course with the chlorine and deal with pH later. Today is going to be a scorcher, so I'll retest the chlorine tonight.

One more question please, at what chlorine level is it unsafe to swim? We won't be around today so it's not an issue. I was thinking of shocking again tonight, or at least maintaining 20 for one more night to make sure whatever was in there is dead. Is it necessary? Thoughts? Thanks so much for all your help!

Thanks a bunch!

 

[JasonLion]

From your description it sounds like you lost 4 ppm of chlorine overnight. If so, you are not done shocking yet, though you are very close.

The PH test result is not reliable when FC is above 10. That could account for why your PH keep "changing".

You can swim at any FC level below shock level for your CYA level.