Chemical Pool Questions (pH and Phosphate)

[TX Pool]

So I am new to operating the pool and plan on doing all of the testing on my own once I get my feet under me for operating and testing. I have the TF test kit but have not had the time yet to fully read all of the instructions and use the kit (life has been pretty crazy). I do have some AquaCheck 7 strips I have been using to get me by and we took a sample to the pool store today as a check; in general what they said about the chemistry was in line with the test strips but I had a few quick questions about the information. Pool is a vinyl liner pool; started it up with floating chlorine pucks but planning on converting it to SWG very shortly so purchased a few gallons of 10% bleach to adjust chlorine as needed until the SWG is up and running in a few weeks:

1. Since I did not install the pool I do not have the exact volume of the pool. I have taken some measurements and it is around 20,000 to maybe 25,000 gallons depending on how I run the numbers. Is it better tp pump the lower volume in the pool math app so you do not over add chemicals and then adjust as I start to learn the pool?
2. The chlorine was a little low so I added some bleach and overshot just a little but the free chlorine was still ok; I was not sure if this is because I had too much volume in the pool math or adding the liquid bleach is that sensitive.
3. The pH of the pool needs adjusted as it is high; they did not have any chemicals at the pool store and they suggested just using muriatic acid by diluting it in a five gallon bucket of water and then adding it to the pool in quarters of the total amount needed once every four hours. I know there is a difference between dry acid that the pool store sells and muriatic acid and was not sure if one was better or anything to be aware of with the vinyl liner pool.
4. The test said the phosphates were super high in the test 2,074 ppb; I cannot remember if the test strips looked at that or if it was how we took the sample into the store. Is it work buying a special chemical to treat for this or would it be best to just tackle the pH first and then retest to see if anything else needs addressed.

Thanks!!

 

[PoolStored]

1. Since I did not install the pool I do not have the exact volume of the pool. I have taken some measurements and it is around 20,000 to maybe 25,000 gallons depending on how I run the numbers. Is it better tp pump the lower volume in the pool math app so you do not over add chemicals and then adjust as I start to learn the pool?

Start with 22,500. Make chemical changes and retest after 30 minutes. If you overshot, reduce pool volume by 500. If under, add 500 gallons to pool math. Rinse, repeat. When additions match expectations, you have your pool volume.

2. The chlorine was a little low so I added some bleach and overshot just a little but the free chlorine was still ok; I was not sure if this is because I had too much volume in the pool math or adding the liquid bleach is that sensitive.

See above. Being over on FC is not an issue. Being under leads to algae.
Follow this-->FC/CYA Levels

3. The pH of the pool needs adjusted as it is high; they did not have any chemicals at the pool store and they suggested just using muriatic acid by diluting it in a five gallon bucket of water and then adding it to the pool in quarters of the total amount needed once every four hours. I know there is a difference between dry acid that the pool store sells and muriatic acid and was not sure if one was better or anything to be aware of with the vinyl liner pool.

Do not use dry acid. Use muriatic. Do not premix. Use goggles. Pour in a pencil thin pour from the jug over a return. Pour downwind. ALWAYS add acid to water.

4. The test said the phosphates were super high in the test 2,074 ppb; I cannot remember if the test strips looked at that or if it was how we took the sample into the store. Is it work buying a special chemical to treat for this or would it be best to just tackle the pH first and then retest to see if anything else needs addressed.

Ignore phosphates. If you keep your FC in range for your CYA, that will keep algae at bay.

I do have some AquaCheck 7 strips I have been using to get me by and we took a sample to the pool store today as a check;

Ignore the strips and stay out of the pool store. Your test kit is the GOLD STANDARD for testing. Use it. If you rely on test strips or pool store testing, you may add stuff you don't need or don't want. Break out that test kit!

Sincerely,
PoolStored.

 

[drsipe]

I'm sure that others will chime in, but test strips and pool store testing is unreliable and without a full set of reading, it's not good to give advise because without complete and good reading, we could ill advise you and cause additional issues.

One word of warning on lowering PH (and at this time I'm not advising adjustment to PH) dry acid adds sulfur to the water which is not good for a salt water chlorine generator. For lowering PH muriatic acid is prefered.

 

[Texas Splash]

Your test kit should have instructions, but here is a link to them as well. Avoid the pool store and their advice at all costs. It will only confuse and frustrate you. We trust your testing over theirs.

Also make sure to update your signature and include the test kit you purchased so we know on each post. It helps with replies.

Extended Test Kit Directions Archives

www.troublefreepool.com

 

[TX Pool]

OK so I got home last night and got out my TFTest Kit and luckily I had spent the few extra dollars and got the pH meter to make testing a little easier. The pH was around 8.0 when I tested and ended up adding about 48 oz of 13.5% muriatic acid to the pool. I do not know my exact volume but I have pool math set at 21,500 gallons. I tested the water again last night about three hours after I added the acid and the pH read around 7.7; but when I just tested again this morning the pH was back up around 7.8 to 8.0 on the meter. Do you think I should just let the water rest and see if it balances out or would you add some additional acid to continue to lower the pH? I am not sure if the gallons need adjusted on my pool math yet or if it is just getting used to measuring and working through the chemistry. A

 

[mknauss]

Post a complete set of test results please.
pH is fine in the 7's.

 

[TX Pool]

Post a complete set of test results please.
pH is fine in the 7's.

OK on a break I will test re-test all of the results and post them

 

[TX Pool]

Post a complete set of test results please.
pH is fine in the 7's.

Ok here are the results I got using the TF-Pro Kit and the digital pH probe that I added onto my kit. I should say currently the pool was opened with floating chlorine tabs; they are all gone and with the rain the past few days I added some 10% liquid chlorine when the level dropped low. In the next couple of weeks I am converting to SWG and will add the liquid chlorine as needed until it is up and running.

FC = 4.5 ppm
CC = 0.5 ppm
TC = 5.0 PPM
CH = 300 PPM
TA = 220 PPM
CYA = 50 PPM
pH = 8.0
Temp = 61

So when I put into pool math:
1. It does not seem too worried about pH although it is outside of the ideal range
2. I know CYA is low for SWG and that is on my list to fix.
3. It looks like TA is way high but I am not sure how to adjust and if this is why the pH did not change much when I added the acid?

 

[mknauss]

Great.
Your TA is quite high. So you will be adding acid very regularly.
Lower the pH to 7.4 when it gets to 8. Test the TA weekly so you have that number in Poolmath to figure out how much acid to add each time.
Good job.

 

[PoolStored]

In the next couple of weeks I am converting to SWG and will add the liquid chlorine as needed until it is up and running.

FC = 4.5 ppm
CC = 0.5 ppm
TC = 5.0 PPM
CH = 300 PPM
TA = 220 PPM
CYA = 50 PPM
pH = 8.0
Temp = 61

With a CYA of 50, and using liquid chlorine your target FC is 6-8. Need to get that up. You need to test and add chlorine daily. When you get your SWCG running, your targets will change.

Always follow this...Link-->FC/CYA Levels

 

[TX Pool]

With a CYA of 50, and using liquid chlorine your target FC is 6-8. Need to get that up. You need to test and add chlorine daily. When you get your SWCG running, your targets will change.

Always follow this...Link-->FC/CYA Levels

Do you know if pool math will auto adjust the FC needed based on the input CYA?

 

[TX Pool]

Great.
Your TA is quite high. So you will be adding acid very regularly.
Lower the pH to 7.4 when it gets to 8. Test the TA weekly so you have that number in Poolmath to figure out how much acid to add each time.
Good job.

Is it worth trying to lower TA? If I understand correctly the only real way to lower would be to maybe get a floating aerator and over time that would help with TA.

 

[reggiehammond]

Lowering TA is easy. Buy 31.45% Muriatic Acid (not the half strength you've bought previously) and use Pool Math to calculate amount needed for 8.0 down to 7.2. Add that amount - a few days later, pH will have risen enough to add again. Keep doing this until your pH stabilizes (though if you have high TA fill water, you'll repeat this dance all summer.)

TA is not something you need to dial in immediately - just follow the process and it'll lower eventually. The only downside to high TA is that your pH will rise more quickly than normal.

 

[drsipe]

Acid lowers PH & TA.
Aeration increases PH, which allows you to add acid to lower both PH & TA

For further reading:

Lower Total Alkalinity

A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.

www.troublefreepool.com

 

[reggiehammond]

Do you know if pool math will auto adjust the FC needed based on the input CYA?

It does.

 

[PoolStored]

Do you know if pool math will auto adjust the FC needed based on the input CYA?

Yes, it will adjust the FC target range. Just keep it at the high end of the range to handle variable demand.

 

[TX Pool]

Yes, it will adjust the FC target range. Just keep it at the high end of the range to handle variable demand.

I have read a bunch on this forum and on the web about phosphates. I understand it is not worth lowing just to lower, but if I am using as part of a program to keep low to help prevent algae growth during times of a low FC that would make sense. I did find one reference out on the web that indicated it could cause health impacts if you swam in water above 2,000 PPB but there was no reference to where that claim came from or what "health impacts" it could cause. I was just wondering if anyone had come across an upper limit that does impact the safety of the pool?

 

[reggiehammond]

Keep your pool properly chlorinated and you can 100% ignore any reference to phosphates you find on the internet. It's a complete nothing-burger.

 

[Newdude]

I understand it is not worth lowing just to lower,

Excellent.

but if I am using as part of a program to keep low to help prevent algae growth during times of a low FC that would make sense

What makes sense is the IC60 program. I'm on that exact program and it is a GREAT program.

Don't skimp on FC, only to need expensive phosphate removers. Set the IC60 to high target or above and phosphates are irrelevant.

I did find one reference out on the web that indicated it could cause health impacts if you swam in water above 2,000 PPB

Was it a respected, peer reviewed type medical site, some rando with a blog , or from an industry source with something to sell? My interest in the article varies accordingly between those 3, and for 2 of them i don't get past the title.