Low pH and High Alkalinity

Problems relating to pH and total alkalinity.
Increase ph, increase TA. Reduce pH, reduce TA.
pH chemistry advice and techniques for the pool.

Low pH and High Alkalinity

Postby Guest » Thu 26 Aug, 2010 11:33

My ph is about 7.2 and my TA is 400ppm

Where do I get a test kit that tests for calcium and cyanuric acid

this schedule was recommended by the company that put my pool in

I will try to find this test kit and get you the results
thanks for the quick response

Allen G Myerson

Low pH and High Alkalinity

Postby Allen G Myerson » Thu 26 Aug, 2010 14:30

With a pH of 7.2, you do not want to add any acid.

You can go to the pool store to get your water tested. You should also be able to order a good test kit, such as the Taylor K-2006.

Here is the K-2006 rebranded by Leslies.

Where do you live?

Low pH and High Alkalinity

Postby Guest » Fri 27 Aug, 2010 19:42

hi Allen,
I bought some test strips so I could get some resluts. they are reading pretty much the same as the test kit I already have however this one has a few more tests

total hardness-250ppm
total chlorine-5ppm
total bromine-10ppm
free chlorine-2ppm

why do you suggest I have a bad schedule. I should add pool perfect or algae backup every week?
please let me know where I should go from here. I know the summer is almost over but I would like to get on top of this and prepare for next year
thank you
Allen G Myerson

Low pH and High Alkalinity

Postby Allen G Myerson » Fri 27 Aug, 2010 20:50

How did your Total Alkalinity get so high? Have you added any sodium carbonate or sodium bicarbonate?

What are the levels of Total Alkalinity and Calcium Hardness in your fill water?

Is your fill water from the city, or is it well water?

I need to know the "Calcium Hardness" in your pool and in your fill water, not "Total Hardness".

You need a more accurate Cyanuric Acid test than you can get from test strips. Make two samples of your pool water. Make the first one with 4 parts of distilled water and 1 part of pool water. Make the second sample with 9 parts distilled water and 1 part pool water, and have them tested at the pool store. Multiply the first result by 5, and the second result by 10. The results should be reasonably close.

Your schedule is bad because you are adding more and more cyanuric acid when the level is already way too high. You need to stop using chlorine sources that contain cyanuric acid.

You need to begin to use liquid chlorine (12 % sodium hypochlorite) or regular, unscented 6 % bleach (6 % sodium hypochlorite) as your primary source of chlorine. Keep your Free Chlorine at 15 ppm until you get your cyanuric acid down. You need to keep a free chlorine level of at least 5 % of your cyanuric acid level to keep algae away.

I see that your pH has gone from 7.2 to 8.4. That is probably due to test error, but it could also be due to the high Total Alkalinity. High chlorine levels can interfere with the pH test. With you Total Alkalinity being so high, it's important to keep your pH lower to avoid Calcium Carbonate scaling. Keep adding acid to keep your pH at 7.2 until your Total Alkalinity comes down.

Test strips are really not very accurate or reliable. You need to get a good test kit.

You need to get your cyanuric acid to below 90 ppm. To do this you are going to have to drain off part of your water and refill. Don't drain below your ground water level or to lower than 1 foot in the shallow end, or your liner could float, or lose its set. You will have to do this a few times to get your cyanuric acid to less than 90 ppm.

You can ignore the Bromine readings on the test strips unless you have ever added bromine or bromide.

You are reporting a total chlorine of 5 ppm and a free chlorine of 2 ppm; is that accurate? That means that your combined chlorine is 3 ppm. You need to get an FAS-DPD test kit such as the Taylor K-2006.

The first thing you need to do is add acid to get your pH to 7.2. Add 1 gallon and allow 1 hour for the acid to mix and react, and then retest. If it is still high, add some more acid, wait another hour, and retest.

Once you get the pH to 7.2, add enough liquid chlorine to bring your Free Chlorine up to 15 ppm. Add 9 gallons of regular, unscented 6.0 % bleach (Clorox or store brand Ultra Bleach). Make sure to get unscented, regular bleach and make sure that the label says 6 % sodium hypochlorite. Don't get "Splashless" or other special bleach. Or, you can get 12 % liquid chlorine and use half the amount (4.5 gallons).

Forget about Pool Perfect, Phos-Free and Algaecide. You really don't need them.

Also, go back and reread chem geek's post. Always pay close attention to chem geek, he knows more than almost anyone. Click on the link that he gave for "Pool School".

Low pH and High Alkalinity

Postby Guest » Fri 27 Aug, 2010 21:50

I have well water and I do not add soft water. There is no other way to solve the cyranic acid unless I drain the water? I will have to have water trucked in.

I dont think my pool company has a clue how to maintain a pool unless they are telling me BS to buy chemicals. I went through 6 50 gallon buckets of 3" chlorine sticks becuase I kept the chlorine high to avoid the algae. would have benn nice to tell me before I screwed up my pool

I will order a good kit
Allen G Myerson

Low pH and High Alkalinity

Postby Allen G Myerson » Fri 27 Aug, 2010 23:53

Unfortunately, there are few options to having a high cyanuric acid level.

Some areas have reverse osmosis treatments available. Reverse osmosis is only available in a limited number of locations, like southern California and Arizona. Check around in your area for availability.

Another option is to add sodium bromide, which would convert your pool to bromine. Bromine does not combine with cyanuric acid. Once you add sodium bromide, the process is pretty much the same as chlorine. You just add bleach on a regular basis to oxidize the bromide to bromine. You won't get much sunlight protection from the cyanuric acid, but you will get some.

There is a bacteria that some people get that converts cyanuric acid into ammonia, but that's really not a treatment option.

Draining and refilling to dilute is usually the best option. You should be able to use your well water unless it contains a lot of metals, such as iron.
Allen G Myerson

Low pH and High Alkalinity

Postby Allen G Myerson » Sat 28 Aug, 2010 01:20

Also, do you have a heater?

Is there any copper in the water?

Have you ever used any type of copper product such as copper-based algaecide or an ionizer?

Remember that you have to subtract one third of your cyanuric acid level from your Total Alkalinity to get your Carbonate Alkalinity. You want to get your Carbonate Alkalinity to about 100.

Low pH and High Alkalinity

Postby Guest » Sat 28 Aug, 2010 06:57

I live in the Chicago area
I do have a heater.

It willbe expensive for me to change out the water. I dont think I will do it this year because the season is almost over. When the company opens the pool next year I will drain it down more and get water trucked in. Everything I have read is to get new water. I wish I knew all this before hand. A pool seems more complicate dthan a thought until you learn about all the chemicals
The compnay insists on people doing the schedule I do. Some of friends barely do anything to their pool and theirs is crystal clear. what a bummer.
I have never added anything copper.
Allen G Myerson

Low pH and High Alkalinity

Postby Allen G Myerson » Sat 28 Aug, 2010 20:31

Why can't you use your well water?
James Watson

Low pH and High Alkalinity

Postby James Watson » Mon 30 Aug, 2010 10:36

You're better off dealing with this as soon as possible. Bad chemistry can damage your pool and equipment.

At least get your alkalinity down. Add enough acid to lower the pH to 7.2, and then aerate to raise the pH. Keep doing this until your alkalinity is at a good level.
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Low pH and High Alkalinity

Postby duraleigh » Mon 30 Aug, 2010 11:01

Ditto what James Watson said above. You would be at risk of damage if you left it over winter.
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Low pH and High Alkalinity

Postby Guest » Wed 01 Sep, 2010 20:29

I drained the water to about a foot left in the shallow end as I am going to try an dfix the cyranuric acid level. I haeve lots of alage in the pool since the last couple days.

I am having the water trucked in- any advice to get this pool crystal clear again as the new water is being dumped in

I will check all the chemicals tomorrow evening.
Should I dump liquid chlorine in? how many gallons?
James Watson

Low pH and High Alkalinity

Postby James Watson » Wed 01 Sep, 2010 20:56

Get your pH down to about 7.2 and use liquid chlorine to raise the chlorine to about 25 ppm. Maintain 25 ppm until this clears.

You are going to need an FAS-DPD test kit to measure the chlorine at these levels.

If you get a chance, please post a full set of new readings.
James Watson

Low pH and High Alkalinity

Postby James Watson » Wed 01 Sep, 2010 21:00

You can use the pool calculator to calculate how much regular, unscented 6 % bleach or liquid chlorine to add to increase your FC level.

Low pH and High Alkalinity

Postby Jimbo » Sun 05 Sep, 2010 18:30

If you use Tri Chlor tablets and tri chlor shock and have a strong residual at time of testing it could give you a false PH reading so let the chlorine levels fall and retest. Have it tested at the pool store too as the cheaper home test kit solutions are not as accurate. Try using liquid chlorine to shock and tabs to maintain proper chlorine levels though you will need to use acid but this seems to keep total alkalinity more in line over the long run.

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