High pH Vinyl AGP

[Fancypants]

My father in law asked me to help close his pool. I like using my test kit, and believe in the BBB and the calculator, so I agreed to give him a hand.

His pH was low, around 6.8, so I asked him to go get some Borax.

I added the Borax per the calculator and now his pH is at or above 8.2 (as high as my test kit will read).

This is my own stupid fault, I fat fingered an entry into the calculator, and added 2 boxes of Borax instead of only 1.

So my question is this, do I really need to lower the pH down to recommended levels before closing his pool? What would the negative effects be on a 12,500 gallon vinyl AGP?

Thanks in advance.

 

[jblizzle]

Yes you need to lower it. High pH can help lead to scaling in vinyl just like any other pool. What are the full set of test results?

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[Fancypants]

I thought just this morning, "A full set of results would have been a good idea"

Sat night:
FC: 1ppm
CC: 7ppm
CYA: 45
TA: 40
pH: 6.8 (or lower, as low as the test will read)

Sunday afternoon I added enough chlorine to bring the pool up to shock levels as well as added the Borax (2x too much) to bring up the pH. I then tested after dark and got the following:
FC: 17
CC: 1
pH: 8.2

I now have 2 new questions:
1.) Could my high FC levels (due to shocking) make my pH test un-accurate?
2.) What is calcium scaling? I have heard the term mentioned, but because I have never had high pH, I was never to concerned about it.

Thank you.

 

[UnderWaterVanya]

Yes pH when measured with FC of 10 or higher will read high. Did you add acid trying to compensate?

The 7 CC result is what worries me.





- Sent using Tapatalk

 

[257WbyMag]

Are you sure that you didn't reverse the numbers for your chlorine test?

 

[Fancypants]

UnderwaterVanya:
No, I have not yet added acid, I will have to go and buy some at the hardware store on my way home from work today. I have never had high pH before, so I have never needed it before.

The 7 CC is likely because he had a bunch of leaves floating around in the bottom, I was able to get them all out, and stressed the importance of keeping the pool free of leaves until we can get the cover on it for winter. That is also why I brought it up to shock levels.

I went to do a chlorine test this morning for our first overnight loss test, but when I added the powder the sample didn't hardly turn pink. I can't believe that the FC levels went from 17 to close to 0 in one night. I took a rather "shallow" sample because I am wearing long sleeves to work today, and I didn't have time for a second test this morning because I was on my way into the office, I will try testing again tonight.

257WbyMag:
I am sure, I always sit down carefully with my TFT-50 and read the instructions each time, no matter how familiar I am with the test. It is possible however, that I may have typed it in wrong, I will check my paper when I get home tonight, I always leave my written results with my test kit.

 

[Fancypants]

Also, I am a little nervous to add acid, if my pH test is off due to high FC while shocking. Any seasoned words of wisdom?

 

[UnderWaterVanya]

Also, I am a little nervous to add acid, if my pH test is off due to high FC while shocking. Any seasoned words of wisdom?

DO NOT add acid or otherwise adjust your pH until you drop the FC below 10 and remeasure. Since you have a TF-50, who makes your pH test? (The pH test doesn't come with the TF-50 if I recall correctly.)

I thought just this morning, "A full set of results would have been a good idea"

Sat night:
FC: 1ppm
CC: 7ppm
CYA: 45
TA: 40
pH: 6.8 (or lower, as low as the test will read)

Just to recap - you measured this then added the borax and chlorine - right? You'll have to wait for FC to drop before you check it again and then determine what to do.

 

[Fancypants]

Also, I am a little nervous to add acid, if my pH test is off due to high FC while shocking. Any seasoned words of wisdom?

DO NOT add acid or otherwise adjust your pH until you drop the FC below 10 and remeasure. Since you have a TF-50, who makes your pH test? (The pH test doesn't come with the TF-50 if I recall correctly.)

I thought just this morning, "A full set of results would have been a good idea"

Sat night:
FC: 1ppm
CC: 7ppm
CYA: 45
TA: 40
pH: 6.8 (or lower, as low as the test will read)

Just to recap - you measured this then added the borax and chlorine - right? You'll have to wait for FC to drop before you check it again and then determine what to do.

You are correct on all accounts, the TF-50 does not have a pH test, the in-laws had an el-cheapo AquaChem chlorine/pH test kit. I have kept it around for pH, and occasionally I will check chlorine with it, just as a test to see if chlorine is even in the pool, so I don't waste my reagents if not necessary.

Also, the Sat Night numbers were before I did anything, I then added the chlorine/borax Sunday afternoon around 5:00PM, I then tested the FC/CC and pH at 10:15PM Sunday night.

 

[UnderWaterVanya]

You are correct on all accounts, the TF-50 does not have a pH test, the in-laws had an el-cheapo AquaChem chlorine/pH test kit. I have kept it around for pH, and occasionally I will check chlorine with it, just as a test to see if chlorine is even in the pool, so I don't waste my reagents if not necessary.

OK - now for the bad news. The cheapie test may not read accurate pH until the FC is even lower than 10. I have a PoolMaster kit from Home Depot and my Taylor. The taylor is far more accurate. You can keep the test block you have and just buy the taylor reagent and that may work - the shades on the two scales I have are similar if not the same, but the phenol red used in the PoolMaster kit requires a chlorine neutralizer that seems to be only semi-effective (my understanding is that using the neutralizer can lead to high pH results so it's only really effective at modest FC levels...).

In any case, my advice is to get the Taylor kit eventually, but for now measure when FC is lower than 10 and if it still reads high - consider getting the Taylor phenol red to try to get a more accurate pH reading before adding acid. My own experience is that if I followed the PoolMaster pH and acid demand my pH would not be accurately maintained.

EDIT - Thinking about this I see I'm implying the test you have is NOT accurate. To be clear - I am not aware of the accuracy of that pH block - and I am pointing out what problems my non-Taylor pH block has. This does not mean yours is going to follow the same path. I also can't say with certainty that the Taylor is the accurate block - but it tracks with industry info and posts from chem geek etc.

 

[Fancypants]

Tonight at 7:45PM
FC - 7ppm
CC - 0.5ppm
pH - 8.2

 

[Fancypants]

Tonight at 7:45PM
FC - 7ppm
CC - 0.5ppm
pH - 8.2

So, should I address the pH first, or bring back to shock levels tonight?

 

[257WbyMag]

Lower your pH first to below 7.8.