Quick Total Alkalinity Question

[Sleepytime28]

Last year I brought a water sample into the local pool store to have it tested. My water was a bit cloudy. My alkalinity came back at 70 ppm. They recommended that my TA be at 160 ppm. This seems odd considering TFP recommends TA levels for my pool to be between 60 and 80 ppm. Is their a good reason I would want my TA in the 160 range? Seems kinda crazy to me.

I did follow the pool stores recommendation last year and it made my pool super cloudy. I also tried again this year and now my pool chemistry is completely. After I tried raising the TA this year it clouded up again and then had an algae bloom. I am in the process of trying to clear the pool up. Unfortunately I am having issues. I can only assume it's because the pool stores recommendation is bad. My TA at the moment is 110 ppm. Should I bring it back down within the TFP recommended range?

 

[AK-]

TA is not that important. Yes, it will speed up your pH drifting up, but the solution for both, high TA and high pH is the same (Muriatic Acid).

How your other number looks like?

What are you using to test your water?

 

[Sleepytime28]

I'm using a pentair 78HR test kit. It's only a 4 in 1. (Chlorine, PH, Acid Demand and Alkalinity.) I need to get a FAS-DPD test kit and a CYA test kit. So I really don't know my FC, CC and CYA numbers. As of right now my PH is at 7.6 or so. I have been pouring about 1/2 gallon of liquid Chlorine every other night for the last 5 days in the pool. It is really cloudy. I can barely see the bottom. It's not really green. More of a blueish color.

 

[AK-]

Seems the test kit you are using is like a Taylor OTO plus TA. You definitively need to know your CYA to figure out how much Chlorine you need. Also your test is unlikely to accurately measure TC above 5ppm. Go grab a TF-100 as soon as you can.

For a 13.5K gall pool 1/2 gal of 7.5% Bleach adds about 3.1ppm of Chlorine or 3.7ppm if using 10% Bleach. Depending on the conditions you are operating (use of solar cover, sunlight incidence, etc) you may not even be replenishing your chlorine.
Also, by adding LC every two days without knowing your CYA and your FC you are seriously risking going below the minimum FC level (minimum as is below that you are going to have algae).

Without full results of a reliable test kit (See Test Kits Compared) it is hard to guess what is going on in your pool.

BTW, did you add any other chemicals recently?

 

[proavia]

How old is your Pentair testkit?

If you want to follow TFP guidance, you may be better served by getting one of the recommended testkits. Test Kits Compared
The TF-100 or TF-PRO are the best value for residential pool owners as they have more of the reagents we use most.

Sounds like you may have a chemistry issue and may need to SLAM Process. Unfortunately, without a proper testkit you can't actually do that successfully. At this point, your TA is the least of your worries.

 

[Sleepytime28]

Thanks for you feedback. I am working on getting a new test kit. Although I don't want to wait for delivery. Would this test kit be something my local pool store would stock?

 

[MITBeta]

It's unlikely. Just order the TF-100 and add some pool owner patience.

 

[proavia]

Thanks for you feedback. I am working on getting a new test kit. Although I don't want to wait for delivery. Would this test kit be something my local pool store would stock?

No local PS will stock the TF-100.
Order it today - ASAP - and you may have it by Friday or Saturday. While waiting for your testkit to arrive, add about 1/2 gallon of 10% liquid chlorine daily to keep the issue from getting worse. Once the testkit arrives, run a full set of test and post the results here

FC
CC
pH
TA
CH
CYA
Water temperature

Have a look at the PoolMath app. You can share your logs from the app here in the forum.

Also, fill out your signature with your pool and pool equipmemt specs. This will allow us to betterhelp you without needi g to continue to ask for your specs.

 

[Sleepytime28]

It's unlikely. Just order the TF-100 and add some pool owner patience.

Lol. Patience is definitely not my strength. I am ordering a kit now.

 

[Sleepytime28]

No local PS will stock the TF-100.
Order it today - ASAP - and you may have it by Friday or Saturday. While waiting for your testkit to arrive, add about 1/2 gallon of 10% liquid chlorine daily to keep the issue from getting worse. Once the testkit arrives, run a full set of test and post the results here

FC
CC
pH
TA
CH
CYA
Water temperature

Have a look at the PoolMath app. You can share your logs from the app here in the forum.

Also, fill out your signature with your pool and pool equipmemt specs. This will allow us to betterhelp you without needi g to continue to ask for your specs.

I am ordering a kit now. I will get my signature updated and post results when I get them. Thanks!

 

[an1vrsy]

We have all been there as new pool owners or pool owners that relied on pool $tore advice in the past. Pool $tore and TFP methods do not mix. I can imagine you want to have answers as soon as possible. However, the answers you receive here will result in crystal clear water and wallet savings. The moderators and TFP guides here are volunteers and want to help you with your pool without any ulterior motives. To do that we need accurate test results from one of the recommended test kits. You've said you ordered the kit. Post the results after the kit arrives and then you will receive advice that will make sense to you.

 

[Sleepytime28]

Ok Guys. I received my TF-100 today and have been adding a half gallon of liquid chlorine daily. Here are my results.

FC = 12
CC = .5
TA = 110
PH = 7.6
CYA = 25-30

The pool clarity was getting better. Today there was a lot of algae in the bottom of the pool (dead I assume). I vacuumed and now its really cloudy again. Should I vacuum to waste? I assume I need to bring my PH down before I do the OCLT and officially start the slam process. Is this correct? One more question. Can I simply go to the local big box store and buy muriatic acid?

Thanks in advance.

 

[AK-]

FC = 12
CC = .5
TA = 110
PH = 7.6
CYA = 25-30

Those are nice numbers.

Your TA is a bit high, but with a vinyl liner that there nothing to worry about there.
An FC of 12 is right on SLAM level for a CYA of 30. The CYA test is a bit trick.
pH readings are unreliable with FC above 10.

The pool clarity was getting better. Today there was a lot of algae in the bottom of the pool (dead I assume). I vacuumed and now its really cloudy again. Should I vacuum to waste? I assume I need to bring my PH down before I do the OCLT and officially start the slam process. Is this correct?

If you have the ability to vacuum algae (dead or otherwise) to waste that is ideal. Be very gentle while vacuuming to avoid disturbing the water around.
For now forget about pH. As stated above reading as unreliable with FC above 10ppm. Whenever possible you should bring your pH down to 7.2 before starting SLAM.
You don't need an OCLT before you start SLAMming, unless water is clear, CC came down below 0.5ppm and you want to check if a SLAM is really necessary.
BTW, since you are already at SLAM level just keep going with it until the cloudiness is gone, your CC is <= 0.5 and you can pass an OCLT. I'd test in the morning to see how much FC you lost overnight.

One more question. Can I simply go to the local big box store and buy muriatic acid?

Yes, you can get MA at the local big box store, but make sure you are getting the real deal. Some MA are not pure MA and should not be used on a pool. See the Acid Magic section of Acid - Further Reading

Examples:
- This is Muriatic Acid: Transchem Muriatic Acid 1 gal. Liquid - Ace Hardware
- This is Muriatic Acid (Pool Section): https://www.lowes.com/pd/Kem-Tek-2-Gallon-Muriatic-Acid/4570022
- This is NOT pure Muriatic Acid and should NOT go into your pool: https://www.lowes.com/pd/Klean-Strip-1-Gallon-Safer-Muriatic-Acid/3036169

Also pay attention to the concentration. They are all OK to use, but you need to use the right one on PoolMath to calculate how much you need. Usually the more concentrated it is the less it will cost you to reduce your pH, but arguably the more dangerous it is to use.

EDIT: One last thing... Later you will have to work on your CYA. Anything below 30ppm will burn way too much FC with sunlight.

 

[Sleepytime28]

Those are nice numbers.

Your TA is a bit high, but with a vinyl liner that there nothing to worry about there.
An FC of 12 is right on SLAM level for a CYA of 30. The CYA test is a bit trick.
pH readings are unreliable with FC above 10.


If you have the ability to vacuum algae (dead or otherwise) to waste that is ideal. Be very gentle while vacuuming to avoid disturbing the water around.
For now forget about pH. As stated above reading as unreliable with FC above 10ppm. Whenever possible you should bring your pH down to 7.2 before starting SLAM.
You don't need an OCLT before you start SLAMming, unless water is clear, CC came down below 0.5ppm and you want to check if a SLAM is really necessary.
BTW, since you are already at SLAM level just keep going with it until the cloudiness is gone, your CC is <= 0.5 and you can pass an OCLT. I'd test in the morning to see how much FC you lost overnight.


Yes, you can get MA at the local big box store, but make sure you are getting the real deal. Some MA are not pure MA and should not be used on a pool. See the Acid Magic section of Acid - Further Reading

Examples:
- This is Muriatic Acid: Transchem Muriatic Acid 1 gal. Liquid - Ace Hardware
- This is Muriatic Acid (Pool Section): https://www.lowes.com/pd/Kem-Tek-2-Gallon-Muriatic-Acid/4570022
- This is NOT pure Muriatic Acid and should NOT go into your pool: https://www.lowes.com/pd/Klean-Strip-1-Gallon-Safer-Muriatic-Acid/3036169

Also pay attention to the concentration. They are all OK to use, but you need to use the right one on PoolMath to calculate how much you need. Usually the more concentrated it is the less it will cost you to reduce your pH, but arguably the more dangerous it is to use.

EDIT: One last thing... Later you will have to work on your CYA. Anything below 30ppm will burn way too much FC with sunlight.

Thanks for the response. We are itching to get back in the pool. I too noticed my cya is a bit low. Having the TF-100 is very inciteful. I am looking forward to being able to tell what is going on with the pool.

 

[AK-]

Thanks for the response. We are itching to get back in the pool. I too noticed my cya is a bit low. Having the TF-100 is very inciteful. I am looking forward to being able to tell what is going on with the pool.

First few weeks after I got my TF100 my wife was (rightfully) saying I had compulsive testing syndrome…

BTW, if you can see the bottom, your FC between minimum and SLAM levels, your pH is in the 7s and there is nothing obviously hazardous in the water it is safe to swim. A pool with CYA of 30ppm and FC of 12ppm is going to have about half the HOCl of a pool with CYA of 0 and FC of 3ppm (chemgeek has couple very insightful posts on the subject).