How a Pool Pro Controls pH in a Swimming Pool

Rising pH can be frustrating for many pool owners and pool pros. You can add Acid, and the pH will be restored next week. You may be trying to lower it, but nothing is happening. 

Video Outline:

Controlling pH, specifically rising pH, can be a real challenge.

Water features add to aeration, which raises the pH.

SWG adds to rising pH during their manufacturing process of making chlorine.

pH tends to increase in plaster and PebbleTec Pools. New pool plaster has a very high acid demand, and you will find pH rising in a new plaster pool rapidly for the first six months. 

More stable in Fiberglass and Vinyl Pools.

Control the speed of rising pH by using these three buffers:

Lower ALK around 70-80 ppm

CYA level of 50-80 ppm

Borates at 50 ppm

Think of it like this:

Vegetation buffers reduce overland runoff.

New football helmets buffer hits from other players and act as shock absorbers, reducing concussions by at least 75 percent.

In the same way, low ALK, a proper CYA level, and borate buffer pH slow their rise in a pool. Turning off water features. Reduce Salt Cell output to below 50%.

3" Trichlor tablets also help keep pH lower since they have a pH of under three.

For this reason, limit your 3" Trichlor Tablet use in Vinyl and Fiberglass pools as they lower the pH in those pool surface types. pH below 7.2 can damage equipment, corrode liners, and sting eyes.

Use the LSI to see if your pH might be excellent even though it is high. I recommend the Orenda APP for this.

Test the pH in your pool.

Lower pH with Muriatic Acid 31.45% 

Dry acid 

You can install a Co2 tank to lower pH – more for Commercial Use

Acid Magic is also effective.

To raise Ph, add 20 Mule Team Borax 

You can also add Soda Ash

Baking Soda raises a pool ALK and not pH, so don't use that.

Ultimately, "chasing pH" is unnecessary, and shooting for a target pH of 7.5 is a good rule of thumb. But it would help if you also referred to the LSI to see your pool's ideal pH based on ALK, Calcium Hardness, and water Temp, among other factors.

Side note (not in the video) using adjusted alkalinity:

Adjusted alkalinity is calculated by subtracting one-third of the CYA level from the total alkalinity (TA) reading. For example, if the TA is 120 ppm and the CYA is 75 ppm, the adjusted TA would be 95 ppm.

It is also important to note that you may think your pH is high in your pool when it is perfectly fine at 7.8. Based on the LSI, the ideal ranges may not be suitable for your pool. If you haven't studied or used the LSI in pool balancing, there is no more excellent resource than Orenda. Not only can you use their free LSI calculator, but they also offer three free courses that will teach you how pH at a higher level can benefit your pool. 

Orenda: https://www.orendatech.com/

Many things can cause the pH to rise in your pool. A Saltwater generator produces a byproduct that causes the pH to increase rapidly. Any spa spillway or water feature will cause the pH to rise through aeration. The pool surface in itself can cause the pH to rise. High Alkalinity in the pool can cause the pH to stay high.

pH is the most critical test factor for your swimming pool, and if it gets out of balance, you will encounter many adverse effects. 

Low pH will cause: 

Corrosive Water 

Stains

Etched plaster

Eye & Skin Irritation

Cloudy Water

Increased Chlorine Activity

Destruction of Total Alkalinity

Stretching of Vinyl Liners

Blistering of Fiberglass Pools

High pH will cause:

Scale Formation

Stains

Cloudy Water

Short Filter Cleaning Cycles

Eye & Skin Irritation

Poor Effective Chlorine 

Testing for pH:

Testing once a week is ideal. For a new pool, start-up testing daily for the first two weeks is recommended. However, once a week, you will get a good indication of how stable the pH is in the pool water. There are various ways of testing the pH, such as test strips, basic test kits, and Taylor kits, which use reagents. Alternate testing can be done with the ColorQ Pro7 Photometer and Digital pH testers.  

Lowering high pH: 

If the pH gets high in your pool, the only way to lower it is by adding Acid. Either a dry acid or liquid Acid. Muriatic Acid of 31.45% is the most common Acid used to reduce the pool's high pH. Dry Acid or Sodium Bisulfate is the dry form that can be added to lower the pH. Some test kits, like the Taylor K-2006, will have an Acid Demand Test. This reagent test will tell you how many acids to add to your pool to lower the pH. Depending on the test results, a chart is included with pool gallons and how many pints or quarts to add. 

Raising low pH:

If your pH is low, you can raise it using a base. A base is the opposite of Acid, and it will raise the low pH in your pool rapidly. The best base is Borax, which will raise the pH without raising the Total Alkalinity.  Baking soda (sodium bicarbonate) also works well, but it is mainly used to raise Alkalinity and requires large amounts to raise the pH. Soda Ash (Sodium Carbonate) raises the pH well but raises the pool's Alkalinity, so use Soda Ash if Borax is unavailable in your area.

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