If your pool pH keeps rising, something in the water or your pool system is usually the culprit. High total alkalinity is a common cause, but aeration, saltwater chlorine generators, certain pool chemicals, and even your fill water can also raise pH over time.

And when that happens, lowering the pH may only be a temporary fix. You need to find out what’s actually causing it to rise if you want to avoid constantly correcting it.

In this post, we’ll look at why pool pH keeps rising, how high is too high, and what you can do to bring it back down.

Why Does My Pool pH Keep Going Up?

Pool pH can keep rising for several different reasons. And to complicate the matter, sometimes more than one is affecting the water simultaneously.

Here are some of the most common reasons your pool pH may be going up:

• High total alkalinity. Total alkalinity helps keep your pool’s pH stable, but when it gets too high, it can cause the pH to rise more easily and make it harder to keep in range.
• Aeration in the pool. Waterfalls, fountains, spillover spas, and other features that move the water around a lot can release carbon dioxide from the water, which, in turn, raises the pH.
• Saltwater chlorine generators. Saltwater pools often see pH rise more quickly than other types because the chlorine-generation process can contribute to carbon dioxide loss and increased aeration.
• Chemicals added to the water. Some pool chemicals can raise pH as part of their normal effect on the water, so changes to the products you use can sometimes explain a sudden increase.
• High-pH fill water. If the water you use to top off the pool already has a high pH or high alkalinity, adding it regularly can keep pushing your pool water in the same direction.
• New pool surfaces. If you recently built or resurfaced your pool, the new plaster or other cement-based materials can cause the pH to rise more often while they cure.

The main takeaway is this: rising pH usually isn’t random. If it keeps happening, there’s likely something in the water or the pool system contributing to it, and figuring out what that is will make the problem much easier to manage.

How High Is Too High for Pool pH?

Knowing what can cause your pool pH to rise is one thing, but you also need to know when that rise actually becomes a problem. For most pools, you want the pH to stay between 7.2 and 7.8.

So, if you’re wondering whether 7.8 pH is too high for a pool, the good news is that it’s not necessarily a problem. However, it is right at the upper end of the recommended range. Once the pH starts climbing above that, you’re more likely to see issues like cloudy water, scale buildup, and chlorine that doesn’t work as effectively.

High pH can also make the water less comfortable to swim in by causing eye and skin irritation. So while it may be okay to swim in a pool with slightly high pH, it’s still better to bring it back into range before the problem gets worse.

Plus, if the pH keeps climbing, it can start affecting both the water quality and how well your pool chemicals work.

How Do You Stop Pool pH From Rising Again?

If your pool pH keeps rising, the fix depends on what’s causing it. Lowering the pH with muriatic acid or sodium bisulfate can bring the number back into range, but that alone won’t stop it from climbing again.

So, depending on the cause, here are some ways to stop your pool’s pH from rising again:

• Lower high total alkalinity. If alkalinity is too high, it can keep pushing the pH upward. Getting it back into range can make the pH easier to control.
• Cut back on unnecessary aeration. If fountains, spillovers, or return jets are constantly agitating the surface, reduce their movement.
• Stay on top of saltwater pool chemistry. Saltwater pools tend to see more upward pH drift naturally, so keeping alkalinity in check and testing regularly can help prevent bigger swings.
• Review the chemicals you’re using. If a product you add regularly is raising pH, changing the product or how you use it may help stop it in its tracks.
• Test your fill water. If your source water has high pH or alkalinity, every top-off can contribute to the problem, so it helps to know what you’re adding.
• Follow the startup care instructions for a new pool surface. For recently built or resurfaced pools, test the pH frequently and make the recommended adjustments while the plaster or other cement-based finish cures. Regular acid adjustments may just be necessary during this period, and the pH should become easier to manage as the surface cures.

If you’ve made these adjustments and the pH still keeps climbing, that’s usually a sign there’s more going on with the water chemistry than one reading can tell you. A proper water test can help pinpoint what’s actually causing the imbalance and what needs to change.

Get Help Balancing Your Pool Water With Clark Pools and Spas

When all else fails (or you don’t have the time to go through every possible cause and fix), a professional water test can help pinpoint what’s still pushing the pH upward and what needs to change to keep it from happening again. That gives you a more targeted fix instead of continuing to make the same adjustments and hoping they stick.

So, if your pool pH keeps rising despite your efforts to correct it, contact Clark Pools and Spas today. Let us help you get it back in range.