Learning how to raise total alkalinity in a pool is one of those essential skills every owner needs to master before the water starts acting crazy. If you've ever felt like you're constantly fighting with your pH levels—adjusting them one day only to find them completely off the next—you're likely dealing with an alkalinity issue. Think of alkalinity as the "anchor" for your pool's chemistry; without it, everything else just drifts around, usually causing a headache in the process.
Why Does Alkalinity Even Matter?
To be honest, most people focus way too much on chlorine and forget that alkalinity is doing the heavy lifting behind the scenes. In technical terms, it's a buffer. In human terms, it's basically a bodyguard for your pH levels. When your total alkalinity is in the right spot, it prevents your pH from swinging wildly up and down every time it rains or a group of kids jumps in for a swim.
When alkalinity is too low, your water becomes aggressive. It can actually start eating away at your pool's surface, whether that's tile grout, plaster, or even the metal components in your heater and ladder. Plus, it makes the water sting your eyes and dry out your skin. Nobody wants to swim in a giant bowl of mildly acidic soup, right? That's why getting those levels back up is a top priority.
How to Tell if Your Alkalinity Is Low
Before you go dumping chemicals into the water, you need to be sure about what's going on. Usually, you'll notice a few red flags. If your pool water looks crystal clear but your eyes are burning like crazy after five minutes, that's a classic sign. Another big one is "pH bounce," where you test the water, add a chemical to fix the pH, and then check it again an hour later only to find it hasn't moved or has swung to the opposite extreme.
Of course, the only real way to know is to test the water. Most experts suggest keeping your total alkalinity between 80 and 120 parts per million (ppm). If you dip below 80, it's time to act. Grab a high-quality test kit—the liquid drops are usually more accurate than the strips, though strips are fine for a quick check-in—and see where you stand.
The Magic Ingredient: Baking Soda
Here is the best part about figuring out how to raise total alkalinity in a pool: you probably already have the "secret" chemical in your kitchen pantry. Sodium bicarbonate is the primary tool for this job, and that is literally just plain old baking soda.
While you can buy fancy containers labeled "Alkalinity Increaser" at the pool store for a premium price, it's almost always just 100% sodium bicarbonate. If you find a massive bag of baking soda at a big-box hardware store or a warehouse club, it'll work exactly the same way and save you a few bucks.
Step-by-Step: Raising the Levels
Once you've confirmed your levels are low and you've got your baking soda ready, it's time to get to work. Don't just wing it, though. Adding too much at once can overcorrect the problem, and then you'll be stuck trying to lower it, which is a much bigger pain.
1. Calculate the Dosage
Generally speaking, you need about 1.5 pounds of baking soda to raise the alkalinity by 10 ppm in a 10,000-gallon pool.
Do a little bit of math based on your pool's volume. If you have a 20,000-gallon pool and you're at 60 ppm (and want to get to 100 ppm), you need to go up by 40 ppm. That would mean you need about 12 pounds of baking soda. If math isn't your thing, there are plenty of free pool calculators online where you just plug in your numbers and it does the work for you.
2. Don't Add Everything at Once
It's tempting to just dump the whole bag in and call it a day, but that's a mistake. It is always better to add about three-quarters of what you think you need, wait, and then re-test. It is much easier to add more later than it is to fix an "overdose" of alkalinity.
3. Spread it Around
With the pump running, walk around the perimeter of the pool and pour the baking soda into the water. Try to avoid dumping it all in one spot, like the deep end or right in front of the skimmer. You want it to distribute evenly so it dissolves properly.
4. Let the Water Circulate
Wait at least six to eight hours—or even a full day if you have the patience—to let the chemicals fully integrate. Your pump needs time to move that water around and ensure the reading you get next is accurate. If you test too soon, you might get a false high reading because the baking soda hasn't mixed in yet.
What Happens to the pH?
One thing to keep in mind is that baking soda will also raise your pH slightly. Usually, this isn't a huge problem because low alkalinity and low pH often go hand-in-hand. However, if your pH was already on the high side, you'll want to keep a close eye on it. If your alkalinity hits the sweet spot but your pH climbs too high (above 7.8), you might need to add a little muriatic acid or sodium bisulfate to bring the pH back down without tanking your new alkalinity levels.
Common Mistakes to Avoid
Even though the process is pretty straightforward, people still mess it up sometimes. One big mistake is adding alkalinity increaser and pool shock at the same time. These chemicals can react or simply cloud up your water if they haven't had time to settle. Give it a few hours between different treatments.
Another mistake is ignoring the weather. If you know a massive rainstorm is coming, you might want to wait. Rain is naturally acidic, and a heavy downpour can dilute your pool and lower your alkalinity right after you've spent money to raise it. Wait for a clear window of weather so your hard work doesn't literally wash away.
Maintaining the Balance
Once you've figured out how to raise total alkalinity in a pool and you've reached that 80-120 ppm range, the goal is to stay there. Check your levels at least once a week during the peak swimming season.
Things like heavy bather loads (lots of sweaty people and sunscreen), frequent rain, and even certain types of chlorine tablets (which are acidic) will naturally pull your alkalinity down over time. By staying on top of it with small, incremental additions of baking soda, you'll avoid the massive "rollercoaster" swings that make pool maintenance feel like a part-time job.
Wrapping It Up
At the end of the day, pool chemistry shouldn't feel like a high school science lab gone wrong. It's mostly just about balance. If you keep your alkalinity in check, your pH will stay stable, your chlorine will work more effectively, and your equipment will last a lot longer.
So, grab your test kit, see where you're at, and don't be afraid to use that bag of baking soda. It's the cheapest and easiest way to ensure your water stays inviting all summer long. Once you get the hang of it, you'll realize that keeping the "anchor" steady is the secret to a stress-free pool.