How To Raise Chlorine Level In Pool?

Raise Chlorine Level

Are you serious about pool sanitization? Do you really want to raise chlorine levels in your pool? Fine, then you must have known its importance.

Anyways, let’s discuss in brief why chlorine is important:

  1. Chlorine sanitizes your pool.
  2. Both, sunlight and debris contribute to the reduction of chlorine level in your pool.
  3. If you are adding chlorine, it sanitizes and oxidizes the water, resisting contamination process.
  4. With contamination, your pool gets near to unsafe zone due to the growth of algae, bacteria and other microorganisms.
  5. The water turns murky and pH balance will be disturbed.
  6. Reversing back to better state can be extremely costly.
  7. If you ignore at the starting stage, then you must be prepared to burn a hole in your pocket.
  8. The more the water contaminates, the more it is difficult to reverse the situation.

So, you must have now understood that you should be adding chlorine to your pool at a constant rate as the usable chlorine levels in your pool will be continuously decreasing. So just relax and read to know how to raise chlorine level in pool.


How much chlorine to add?

On an average, for residential pools, you need to maintain a level of 2 to 3 parts per million (ppm) of chlorine in your pool. If you have a commercial pool then, you need to add 3 to 5 ppm of chlorine as the pool usage will be more. If you do not follow the ideal levels, then your pool may not be sanitized and might get into unsafe zone.

Don’t overthink and too much chlorine because, if the chlorine level is between 3 to 8 ppm, swimmer finds it extremely difficult. However, up to 5 ppm is acceptable and if the range crosses 8 ppm, then you should forget swimming!

How to raise chlorine level?

Before you start adding chlorine to your pool, you should first know the existing chlorine levels in your pool. Based on the existing level, you must calculate how much chlorine to add. You can decide if you just need slight adjustment or need to shock the pool in case if you have combined chlorine in your pool.

Using chlorinator or chlorine feeder or chlorine floater

  1. Some people add chlorine directly to the skimmer. If you have bought chlorine specifically designed to add to skimmer then its fine. But, if that is not the case, then you should immediately stop this habit as the chlorine will directly travel to your pool equipment and lower pH levels.
  2. Moreover, the water that passes through pool equipment will make it corrosive and damages over time.
  3. Corrosion adds unnecessary metals like copper into your pool. So, now that you know how dangerous it is use skimmer to add chlorine, you should instead prefer chlorinator or chlorine feeder or chlorine floater.

Different ways of raising chlorine levels

Let’s discuss about different ways of adding chlorine to the pool. Each method has its own benefits and disadvantages. Whichever method benefits you the most, you can go for it.

Raising Chlorine levels with Trichlor tablets, sticks, or granules

If you are using an outdoor chlorinated pool then, Trichlor can be a better choice. Trichlor or Trichloroisocyanuric Acid is the most commonly used chlorine additive by many pool owners.


  1. It takes time to dissolve when it is in contact with water. This makes it a better idea to use feeders, floaters or chlorinators.
  2. Trichlor is available in different forms like granules, sticks or tablets.
  3. The cost is comparatively lower than other types of stabilized chlorine.


  1. Trichlor is highly concentrated. Even a slight exposure can burn your skin and mucous membranes. So, be careful to stand upwind and see that you do not breathe in fumes while working with it.
  2. Trichlor is highly acidic and has a pH value between 2.8 to 3.5. This will in turn pressurize your pool pH, thus lowering your pool’s total alkalinity.
  3. Low alkalinity will result in corrosive damage and the direct victims to it can be   and pool equipment. Hence, you need to again work on adjusting pH levels for your pool.
  4. You may need to fix the side effects due to lower total alkalinity in your pool by adding soda ash.
  5. Due to continuously adding Trichlor, cyanuric acid levels of your pool water can increase drastically.

Raising Chlorine levels with dichlor granules

If you are using an indoor chlorinated pool then, dichlor can be a better choice. Dichlor or Sodium dichloroisocyanurate is the most commonly used chlorine additive by many spa and above ground pool owners.


  1. dichlor dissolves faster when gets in contact with water. Best in situations where you are looking for a quick dose of chlorine before you start getting into the pool.
  2. pH will be affected slightly to about 6.7. Hence, dichlor is better option especially in spa pools where pH is difficult to control.
  3. Total alkalinity is not affected.


  1. It is comparatively expensive than trichlor.
  2. If you are planning to use feeders, floaters or chlorinators then dichlor will be bad choice as it dissolves too fast.

Raising chlorine levels by shock treatment

Chlorine based shock can give your quick results. You have two options to choose when it comes to pool shocking – chlorine based shock and non-chlorine based shock.

Chlorine based shock is generally preferred if you are specific about intentionally raising chlorine levels in your pool. The key ingredient used for this type of shock is calciumhypochlorite.

You can shock your pool only when the chlorine levels are raised to above 10 ppm. You can calculate the amount of chlorine to add to the pool by considering the volume of water and the present chlorine levels in the pool.

Follow the instructions mentioned on the shock container and leave it uncovered for some time as you need to let the oxidation gases to escape into air. Avoid chlorine based shock in sunlight as the chlorine levels will be depleted fast during the shock treatment.

Chlorine Categories

Generally, you will get two categories of chlorine in market – stabilized and non-stabilized. The type that is added to pools is the stabilized one. This type of chlorine has cyanuric acid added to it and hence when it is added a sunlit pool, it will stay stabilized. Hence, you should prefer it for outdoor pools and is 3 to 5 times stable when compared to the results you get by adding non-stabilized chlorine. If you are using non-stabilized chlorine, you should cyanuric acid separately to it.

If you want to perform chlorine based shock to your pool then, you must be using non-stabilized chlorine as the stabilized chlorine may result in increased cyanuric acid levels in the pool waters.

Tips to raise chlorine level in your pool

  1. Always stick to single variety of chlorine or else you may end up in mixing different products which can make it difficult to preserve chlorine balance in your pool.
  2. When expiry date approaches, chlorine may lose its effectiveness. So think twice before you use regular retail liquid bleach.
  3. If you have already been using specific chlorine brand without any issues, you may continue the same. However, if you are planning to switch to a different brand, ensure that you test it with some of the portions of the pool waters. This way, you will come to know how much you should add to the remaining portions to avoid excess chlorine levels.
  4. If you have tested and found that cyanuric acid levels have drastically increased then, drain a part of the pool and replace it with fresh water. This will reduce the concentration levels of the acid.

Other Important Articles

Choose chlorine variation that best suits you

It is essential to know how to raise chlorine level in pool. You should maintain proper sanitation for a harmless swimming environment. You should seriously understand how chlorine works to improve sanitation for a pool and how much quantity you should add. You must be aware of different devices used for adding chlorine and also about different variations of chlorine.

If your pool is regularly chlorine-balanced, then you can enjoy safe and sanitised swimming environment, minimum contamination, and above all - minimum maintenance costs on adding chemicals and testing.

Bryan Mallory

My name is Bryan Mallory and I have over 25 years of experience in swimming pool, spa maintenance and repairs. With my experience and knowledge I can return your pool back to its best and keep it in peak condition.