How Does pH Affect Pool Clarity?

Many pool owners are shocked when I tell them that pH affects clarity of the pool. They simply cannot believe it. The basic understanding is that if the pool water is filtered properly, and chlorinated adequately, it should be clear. But that's not true.

If you're experiencing "cloudy" pool water and you know that the pool filtration is done properly, then it's time to pay attention to the pH of the pool.

Why pH?

Although there are many factors as to why a pool becomes "cloudy", pH is by far the easiest to test. pH reading can show if the pool is corrosive or scaling at any given point in time. Most pool test kits can read pH in a matter of seconds.

High pH = Cloudy Pool

High pH makes water scaling. Scaling simply means calcium and magnesium will "come" out of water and become tiny white particles. Water has these minerals, and are invisible to the naked eye. But when the pH becomes high, these minerals will become visible, making the pool "cloudy" white. It's not dirty, but it's just not pleasing to look at.

How to Stop Scaling?

If high pH makes water scaling, then low pH makes it corrosive. At lower pH, calcium and magnesium particles will "melt" and mix it with water again. This step alone will make the pool clear of any white particles floating in the pool. Most pool maintenance personnel keep the pool low in pH to maintain crystal clear look. But it's not advisable to do so since low pH turn water highly corrosive and erodes the grouting of the pool tiles. If vinyl pool, you can experience discoloration and patching of the liner.

What's the correct pH range?

ANSI recommends 7.4-7.6. But my personal experience has shown that a target of 7.2 is quite good. At that pH level, the calcium and magnesium dissolve completely, and give that sought after "crystal clear" pool water. Also, you have that added buffer of pH going up to 7.5-7.6 in a few days so you don't have to adjust it frequently.

How do you lower pH?

I personally use 99% dry acid to bring pH down. Most pool owners use Hydrochloric Acid, famously known as Muriatic Acid. You need to use 35% Concentrated Version. You need to be careful while dosing acid since overdose can lead to corrosion in the pool. To get the dosage right, use this calculator. Added benefit of not overdosing is that you do not need pH increasers.

What if the pool is still cloudy even though pH is 7.2?

If that's the case, then you either have high organic matter, or just bad filtration. Either way, if you do not wish you fix the entire filtration system, you can use a good, high quality clarifier. Clarifier binds smaller particles, clumping them together to form big particles, which can then be easily filtered or vacuumed out of the pool. It lends a helping hand to a poor filtration system. We have our own clarifier called Clear-Up Pool Clarifier, which is excellent at this job. Click here to read more.

If you have any concerns, kindly comment below. Cheers!

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