- If You have free chlorine levels at or below one part per million, it means your pool water isn't sanitized, and that can lead to algae growth and bacteria buildup. But What if you've tried adding chlorine to your pool and the levels just won't go up? If Your free chlorine is low or you're not getting a reading at all, it's time to shock your pool. But If your chlorine continues to remain low, even after shocking,, you may have a chlorine demand issue. So Here's a step-by-step guide on how to raise your free chlorine levels and prevent them from dropping too low.

Let's dive in. Real Quick,! if you want more help taking care of your pool,, be sure to grab our free! Pool Care Cheat Sheet at SwimUniversity.com/CheatSheet. It's totally free and will help keep your pool clean and clear all season long.. First, what exactly is free chlorine? Free Chlorine is the amount of chlorine that's available to sanitize your water.

In Other words,: it's the chlorine that hasn't been used up and is still free to kill contaminants. If There isn't enough free chlorine in your pool,. your water is susceptible to algae growth and bacteria buildup.. Your Free chlorine should be between one and three parts per million, with three parts per million being ideal.

Combined Chlorine, on the other hand, is chlorine that's already been used to fight contaminants in the water. It's also known as chloramine. Your Combined chlorine should be no more than 0.5 parts per million, and if it gets too high,, your chlorine will stop working effectively. And High levels of combined chlorine cause that chlorine like smell in your pool.

Finally, total chlorine is the sum of free and combined chlorine. If Your total chlorine levels are the same as your free chlorine levels,. It means none of your chlorine has been used up and there's no combined chlorine in your water.. Okay, What causes low free chlorine levels? There's several things that can cause sudden or chronically low free chlorine, and you'll wanna figure out the root of the cause to prevent it from happening again..

Number One,, high chlorine demand. If You have lots of swimmers or a lot of debris in your pool, you'll need more chlorine to sanitize the water.. The More contaminants your chlorine has to fight in the water, the more chlorine your pool needs. High Chlorine demand happens when your chlorine has to work overtime and you can't add enough chlorine to keep up with the demand..

It's most common when your water sits untreated and stagnant for the winter. And Heavy rainfall can also cause high chlorine demand, especially if you get runoff from your yard.. If You've just added chlorine to your pool and you still have a low chlorine level,, there's a chlorine demand problem.. In Order to cure chlorine demand, triple shock your pool with a chlorine based shock like Cal Hypo shock.

We'll walk through this process a bit later. Number Two,, sunlight and low cyanuric acid levels.. If You're using unstabilized chlorine like liquid chlorine or bleach,. your chlorine levels will tend to drop in the sun.

That's because the sun's UV rays break down your chlorine if it isn't stabilized with cyanuric acid.. Test your cyanuric acid levels weekly and use a chlorine stabilizer if needed. Number Three,, very high cyanuric acid levels. While Low CYA can cause chlorine issues,.

high CYA can be just as harmful. Your Cyanuric acid levels should be between 30 and 50 parts per million. And high CYA weakens your chlorine's ability to sanitize your water. Your CYA can get too high over time if you use stabilized chlorine like chlorine tablets or granules..

Number Four,, not consistently adding enough chlorine. One Of the simplest reasons behind low free chlorine levels,, there's not enough chlorine regularly added to your pool. And If you use a chlorine floater,, make sure that you have enough chlorine in it to cover your surface area. Likewise, if you use a salt water generator and your chlorine levels are low,, check your salt levels and your salt cell for calcium buildup..

Okay, here's how to raise the free chlorine in your pool. First, clean your pool and remove debris. This means skimming, brushing, and vacuuming. Then, test your water.

You'll wanna make sure your pH and alkalinity are within range before shocking your pool. And If you need help balancing your water chemistry, be sure to check out our other videos. Once Your pool is free of debris and all your other levels are balanced,. it's time to shock.

The Goal of shocking your pool is to add enough chlorine to reach a chlorine break point. This means raising your pool's free chlorine levels to 10 times or more over the normal amount. For Most pools, use Cal Hypos Shock. Cal Hypo is the strongest type of shock available and will quickly raise your free chlorine levels.

Because Cal Hypo's shock is unstabilized chlorine,. Add it to your pool at night so it's not destroyed by the sun's UV rays.. To Reach that chlorine break point, you'll need to triple shock your pool. That means adding three times the amount of shock you normally would.

For Salt water pool owners use dichlor shock. This Shock will help raise your free chlorine level without calcium buildup inside your salt cell.. Keep In mind, that dichlor shock will raise your cyanuric acid levels. So If you're already dealing with high CYA, offer liquid chlorine to shock your water instead.

You'll still need to use a triple dose of shock no matter what type of shock you use. Wait At least eight hours for the shock to work and then retest your water, rebalance your pH and alkalinity if necessary,, adjust your cyanuric acid levels, and start to chlorinate your water regularly. But What if your free chlorine levels don't change after shocking? Well, there are a few reasons why your levels might be low even after shocking your pool. Number One,, your other chemicals are out of balance.

Without The right pH or cyanuric acid levels, your chlorine can still fluctuate. So Make sure these are balanced before and after shocking your pool. Number Two,, a high contaminant load. You may have a buildup of bacteria or algae that requires a more aggressive shock treatment.

So Be sure to check out our other videos about getting rid of algae. If You need more help, grab our free Pool Care Cheat Sheet at SwimUniversity.com/CheatSheet. And If you found this video helpful,, subscribe for more pool maintenance tutorials throughout the season. That's it, thanks again, and happy swimming.