Low Total Alkalinity and Low pH

by Paul
(Enfield CT, US)

Can my total alkalinity be low and my pH both be low at the same time? How do I fix? I have an 18,000 gallon in-ground pool.

Thanks for the question Paul

You can raise the TA and pH with the same product, sodium bicarbonate. Don't get any TA or pH Up from the pool store. It's the same thing only marked up 100 - 200%.

It's 1 lb. of bicarb to raise the TA 10ppm per 10k gallons and the pH 0.2 per 10k gallons.

Broadcast it around the perimeter of the pool with the pump on FILTER. Brush the pool very well, retest the TA and pH after 10 hours and make another adjustment if needed. Do this in small increments not in one large adjustment. If you over-shoot the mark you'll need to lower them using acid.

Remember that low TA and pH fill water will reduce both readings so keep this in mind when you're topping off the pool.

Have a great Summer.


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Can't Raise My Pool Alkalinity Using Aqua Chem Alkalinity Increaser

by Mary Clark
(Virginia beach, va)

I have a 6400 gallon pool, and I have added approx. 12 lbs of Aqua Chem Alkalinity Increaser, but my alkaline is not comming up. What am I doing wrong? The pump is running and I have no other chemicals in the pool.

I'm waiting approx 2 hours to test. I'm very confused. I thought Baking Soda was a decreaser? I'm using store chemicals and it's not increasing at all, I don't think.

Thanks for the question Mary

Baking soda is the perfect alkalinity increaser. Only acid is used to decrease your pool alkalinity and pH. I've used baking soda for years and have never had a problem with it.

Our fill water is 8.2pH and alkalinity is 30ppm. I use about 400oz. of baking soda to raise the YMCA pool 10ppm. First, I would like to see what you're readings are. If you can go back to this page and post them in the comment section, it would help. You'll find your question in the pool Q&A page.

It will be at the top of the "Alkalinity" category under the title "Can't Raise My Pool Alkalinity Using Aqua Chem Alkalinity Increaser". Post your alkalinity readings, then check back every so often to see what my response is. I usually check them several times throughout the day, so you should have an answer fairly quickly.

Be sure you keep the pump motor off when increasing the alkalinity. Let it sit for about 3 hours, then turn the pump motor back on and allow for 1 complete turnover of the water, then retest.

Your pool pump is probably going at around 30 GPM (gallons per minute). That would be 1800 gallons per hour. It would take 3.5 hours to do a complete turnover of the water. You may want to wait 4 hours to retest. Regardless of what anyone says, you MUST wait for a complete turnover of the water to have an accurate reading.

To raise the alkalinity 10ppm for a 10,000 gallon pool, you would use about 1.5 lbs. of baking soda. In your case, you'd use about 1 lb. to raise it 10ppm.

Here's a chart you can look over:

Pool Alkalinity

Start low and work your way up, retesting after each adjustment. This is when you need to have patience, but raising your alkalinity using the above technique will work. I've been doing it this way since 1999 for hundreds of pools and it's always worked.

Hope this helps and let me know the readings.


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Muriatic acid + Alkalinity Up

by Karen
(Hernando County, Florida)

I do not understand why the recommended pool cleaning supply business in our area is having my husband add muriatic acid AND Alkalinity Up to our pool at the same time.

Wouldn't they just cancel each other out? Is the dealer just selling to a sucker?

Thanks for the question Karen

Muriatic acid lowers both the TA and pH. I don't have the information on the pH or TA levels but I can guess the pH may be high, 8.0 or over and that could be the reason for the acid use.

Many pool owners do have a low TA and higher pH problem. It's one of the more difficult chemical adjustments to make so you'll need patience and consistency to get both readings in the right range.

I would encourage you to use regular baking soda to increase the TA. It's much cheaper and is exactly the same thing the pool store uses. Costco has a 13 lb. bag for about $8. Pool stores sell it at $10 for 1 lb.

It's 1 lb. of baking soda to increase the TA 10ppm per 10k gallons. With the pump OFF put the bicarb in the deep end and allow to sit for 3 - 4 hours. turn the pump back ON and FILTER for 12 hours, retest and make another adjustment if needed.


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How To Increase Stabilizer Without Decreasing Alkalinity.

by Scott
(Racine, Ohio)

How do I get my stabilizer levels high enough without lowering my total alkalinity levels.

Thanks for the question Scott

The stabilizer, or cyanuric acid (CYA) in chlorine tablets, is just that, acidic.

When you put acid in the swimming pool, it will affect both the pH and alkalinity.

For every 10ppm of chlorine added with Trichlor tablets, you'll increase your CYA by 9ppm.

To the best of my knowledge there's really no "easy" way to increase the CYA using chlorine tabs without possible affecting either the alkalinity or the pH.

It depends on where your CYA and alkalinity readings at the moment and where you want them to be.

Your CYA should be between 30 - 50ppm (with the chlorine 1.5 - 3.5ppm) and alkalinity between 80 - 100ppm. You can go up to 120ppm and still be in the safe zone.

If your CYA is around 20ppm and you want to raise it to 30, then that's really not a big jump.

But if you're starting the CYA from zero, the excess acid may chew into your alkalinity.

Dichlor will have least effect on total alkalinity. This is a stabilized form of chlorine that is used for shocking and manual dosing.

For every 10ppm chlorine increased using Dichlor, you'll increase your CYA by 6ppm.

For the least affect on your alkalinity, you can use Dichlor and you'll be adding CYA to your pool.

Hope this clears it up for you and have a safe and fun swimming season.


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Alkalinity Title

by Patrick
(Allen, TX)

Hi Robert,

Thanks for giving us very helpful information on things pertaining to pool and spa.

I was checking your topic about Alkalinity. Correct me if I am wrong but, the title of your topic about sodium bicarbonate should have been how to raise alkanity instead of lowering alkanity.

As you have pointed out, Decreasing alkalinity would need muriatic acid, while increasing alkanity would need sodium bicarbonate.
Both titles under Alkanity states reduction instead of having one to point otherwise.

Thanks again for all your instructions. More blessings to you.

Thanks for the catch Patrick. Good call. I guess even the best will chase the occasional one that's low, outside, and in the dirt.

Have a great day.


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