Pool School 106 Stabilizer

Stabilizer25lbBkSmallWebStabilizer has many different names in the swimming pool industry so this chemical can sometimes be confusing to the swimming pool owner.  The actual chemical, cyanuric acid, is also called conditioner in addition to the classic stabilizer.  Confusion usually occurs from cyanuric acid’s common name “stabilizer” as most people think it does something to balance and stabilize the pool water, however this is not what it is designed to do.  Stabilizer’s sole purpose in your pool is to provide protection for you chlorine from the UV rays of the sun.  Think of it as sunscreen for your chlorine.

If you did not have the correct level of stabilizer in your pool what would happen is you could chlorinate the pool in the morning, and within several hours the chlorine would be down to zero.  When you have zero chlorine in the pool the water will be un-sanitary and algae will begin to multiply because nothing is in the pool water to stop it.  Then at the end of the day, after the sun is off the pool, your chlorine level would recover.  Then the next day when the sun comes up you would go through the cycle of no chlorine again.  Each time that happens the algae and bacteria make bigger advances.

So in order to avoid this problem, stabilizer is added to the pool water, and acts as a guard to protect your chlorine from UV light, keeping the chlorine at the proper level all day long.  With the stabilizer in the water the chlorine level stays constant, so the chlorine is there all day long to stop algae and bacteria from having a party in your pool.

The amount of stabilizer you want to maintain in your pool will depend on the type of sanitizer you add to your pool.  If you are using stabilized chlorine tablets you will want to maintain at least 25-ppm of stabilizer.  If you have just refilled the pool you will need to give your water a little boost of stabilizer to get going and the stabilized chlorine tablets will build your stabilizer level from there.  If you have a salt generator, use Calcium Hypochlorite or Sodium Hypochlorite then you will have to add additional stabilizer.  With these systems you want to maintain between 50-ppm and 70-ppm.  Chlorine is the only sanitizer that can be protected from UV light and some systems do not require stabilizer because they are not affected by UV light.  For more information about other forms of sanitizers see Aegean Pools Pool School 101 on Word Press.

Another misconception about stabilizer is an issue some pool professional’s call “chlorine lock.”  Some companies will tell you when your stabilizer is over 100 ppm you will need to drain water out of the pool to lower the level.  If you have a commercial pool this would be true, because the health department requires the stabilizer be less than 100 ppm.  This is because of the high volume of people introducing contaminants into the pool water; high levels of stabilizer can interfere with chlorine’s ability to sanitize the water.  In residential pools you will be fine until you hit the 150-ppm to 175-ppm level.  The problem with stabilizer is that it adds solids to the pool water, imagine if you will a football field, if you were going to walk from one end to the other to retrieve something at the other end, it wouldn’t take you any time at all because there is nothing blocking your path.  Now imagine that same football field as a jungle, if you now have to hack your way across that same area it is going to take you a lot longer to reach your goal of the other end.  This is the type of problem that the chlorine encounters when the stabilizer level is over 150 ppm it increases the time it takes for the chlorine to sanitizer the pool water.

You only loose stabilizer from the addition of fresh water or a special cyanuric acid lowering chemical.  So as you add water to make up for splash out, you vacuum the pool to waste, or it rains in the pool you will loose stabilizer and need to compensate for the loss of stabilizer by adding additional stabilizer.  How much will depend on how much water you added to the pool.  The best way to decide if you need to add additional stabilizer is to test the water or have the water tested at Aegean Pools.  If you need to lower your stabilizer you can either dilute it with fresh water or add stabilizer remover available at Aegean Pools.

One of the most difficult things about stabilizer is getting it dissolved into the water.  The product is very hard to dissolve.  If you were to throw it into the pool and let it sit on the bottom of the pool it would take over a month to dissolve.  So what we have our customers do is add it to the filter so the water will run over it at a high velocity.  Even with the high velocity the stabilizer will still take at least 2 days to completely dissolve and longer if the water is below 70°.  The concern about adding stabilizer to the filter is how you have to add it.  At Aegean Pools we have specific instructions for adding stabilizer to your filter system, and if you don’t follow them correctly, you could end up with a plugged skimmer line.  When stabilizer gets stuck in the piping it will set up like concrete and it will take, and I don’t exaggerate when I tell you this, years for it to open up again.  If you don’t want to hassle with the possibility of plugging your skimmer line we offer Instant Conditioner (liquid stabilizer) that will make the addition of stabilizer a snap!  You just shake the bottle well and pour it around the pool, done!

And we are done for this class; don’t forget to be on time for our next class!


7 thoughts on “Pool School 106 Stabilizer

    • Hi Nancy,

      Honestly, that is a sentence I do not like to hear. There are not a lot of choices, very rarely can you ever un-clog a plugged stabilizer skimmer line. The problem is as indicated in the Pool School session is that stabilizer sets up like concrete and the only thing that will dissolve it is water. The problem is it takes a very long time to dissolve. Depending on how much stabilizer is clogged in the pipe it could take anywhere from one to four years for it to un-clog. You can see if you can find a plumbing company that can root the pipe out without damaging the pipe, very rarely is this successful because of the type of plumbing most in-ground swimming pool companies employ. The only other option is to have a new pipe run from the filter to the skimmer, this is not always easy to do. Sorry I cannot be more encouraging, but the best way to avoid this problem in the future will be to use Natural Chemistry’s Instant Conditioner. It is a liquid form of stabilizer. It is more expensive than using the dry form but, if you consider the cost of re-plumbing your skimmer in the long run it may be less expensive.

      • Isn’t that the truth. I did make progress after running a snake about 40 ft into the pipe. The pump is not running as hard and the psi returned to what it usually is.
        After using this product which was recommend from the pool store I purchase from I am surprised that more instruction was not given.
        I certainly won’t buy it again very difficult to use.
        Thank you so much for this site and the tips and advice you give.
        Regards – Nancy

  1. So I screwed up and added the stabilizer granuales directly to the pool. I thought that was what they told me at the store. Now what do I do???

    • Hi Coleen,

      Well, if you are going to screw up it is best to keep it to a minimum, and you have been successful at doing just that. The solution is simple; just manually vacuum the pool with the multiport valve (if you have one) in filter position. This will draw the stabilizer into the filter. Then don’t backwash your filter for at least 48 hours and you should be fine. If you leave it in the pool it will take over 30 days to dissolve.

      Jim Garrison
      The Guru of Pools
      at Aegean Pools

  2. Hi…similar problem as Colleen..added stabilizer directly to pool…except I have one of those intex pools do it yourself pools and no fancy vacuum or skimmer…just the pump …any other way to get the granules to dissolve? And is it safe to still swim in it? Thanks for your help!

    • Hi Sara,

      The problem with your type of pool is you do not have a way to get the granules into the filter system. In this situation I would recommend using Natural Chemistry’s Instant Conditioner. This product is a liquid form of stabilizer/conditioner, and is easy to apply to the pool water simply shake it up really well and pour it into the pool water. It is available at our retail store. The key concern is you have a chlorine residual in the pool water at least 1ppm to ensure the pool is safe for swimming.

      Jim Garrison
      The Guru of Pools at
      Aegean Pools

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