CYA, or Cyanuric Acid, is one of those chemicals that really isn't understood like others. Pool stabilizer one of those chemicals that can be good for your pool but also a detriment. So in this blog we're going to be talking about what stabilizer is, what it does, what are the recommended ranges and also what can happen if it's out of range.
So what is CYA?
CYA is the only chemical in the water that protects the chlorine from the sun. I refer to this chemical as sunblock. I explain that it's a two faced chemical, and when I say that, my clients immediate ask, "What do you mean?" What I mean by that is if the it protects the chlorine up to a certain point but any point after that it turns into handcuffs and actually prevents the chlorine working as efficiently as it should be.
What are the recommended ranges?
According to the NSPF the recommended range for CYA is 30-50ppm. Anything under 30ppm you'll see that the chlorine experiences 'burn off' and almost leaves as quickly as it gets in the water. If you have a pool with 0 pool stabilizer and put in a gallon of liquid chlorine you can expect it to be burnt out in only a few short hours. Now, if it's above 50 you need more chlorine for it to keep your pool clean and healthy. If either reading is extreme then you can easily end up with a green pool.
Why is that?
That is because the chlorine and pool stabilizer have a specific relationship that must be kept in order for your pool to be balanced and your sanitizer working right. The chlorine needs to be 7.5% of the stabilizer reading. I always give the example of 100 for easy math. So if the stabilizer reading is 100 that means the chlorine needs to be 7.5ppm (nearly double of the max recommended range by the NSPF) in order to keep the chlorine working efficiently. The higher the CYA goes, the more chlorine you need to keep that relationship true.
How can you adjust it?
Well, if the pool stabilizer is low you can use chemicals to raise it. You can use pure CYA or you can use stabilized chlorine such as trichlor and dichlor granular, or 3 inch tablets. Those 3 all have stabilizer in it. If it's low there are only two ways to lower it as there is not a reliable chemical to lower it. You can either use water replacement (i.e. drain and refill) or you can use reverse osmosis. The ladder is very expensive.
I hope this helps out and allows you to learn a little more about stabilizer. Also please check out my YouTube video about stabilizer and also my podcast discussing all of this.