Cyanuric Acid, Stabiliser or Sunscreen are just a few names used by Pool Chemical Companies to describe this product but for the purposes here let’s call it stabiliser.
Stabiliser basically protects your pool chlorine from the UV radiation of the sun. The right level will protect, too little and the sun's UV rays will eat your pool chlorine, too much and you will cause chlorine block.
If your pool is Chlorine Blocked it’s bad for 2 reasons.
First because it’s not sanitizing your pool so you can pretty much guarantee its turning green no matter how much chlorine or other chemicals you add, it’s just not going to change.
Secondly because you are going to have to drain part of your pool water out and refill it to dilute the pool water enough to get rid of the excess stabiliser.
Hence the tried and tested practice of "Always test your pool water BEFORE adding ANY chemical" and "Read the packet first" for example some chlorine products are stabilised meaning they contain stabiliser in some form most commonly it will have a "CYANURATE" as an active ingredient.
This is the most common way a pool will end up with excess stabiliser.
Correct levels of stabiliser should be between 30ppm to 50ppm in your home test kits, dosage levels should be as directed by the manufacturer of your product and will depend on what your current levels are.
As for the question: -
What time of day should I add stabiliser?
Best time of day to add stabiliser to your pool is sundown (or dusk).
This way you will be able to see what you are doing and the stabiliser will have all night to disolve and bond with your chlorine before being hit by the UV radiation of the sun or use by your family and friends.
Remember, if you add chemicals and then backwash your filter you are literally flushing money and chemicals down the drain.
If you add chemicals before you increase your water level you’re also going to have to retest and possibly add more chemicals as you have just diluted the chemicals you just added.
So when it comes to adjusting your chemicals follow these general steps: -
- Clean your pool.
- Empty your skimmer and pump basket.
- Backwash your filter or clean your cartridge.
- Re-adjust your pool water level.
- Test your water.
- Add your pool chemicals acid products first, wait 20 minutes then alkaline products.
Many people will tell you how and where to add Stabiliser.
Some of the different ways I have heard "EXPERTS" say is the "ONLY WAY" to add stabiliser to a pool.
"Put it on the steps" - Problem here is that young children can scoop it out and eat it. "Put it in the deep end" - Problem here is stabilizer takes a long time to dissolve and there isn't much water movement in the deep end so it sits for a long time.
"Dilute it in a bucket then spread it around your pool” - Probably the fasted way to get the stabiliser to have an impact in your pool but it still takes a long time to dissolve in the bucket.
"Spread the packet around the pool and let it dissolve" - Probably the most effective way to ensure even distribution in a way that will ensure children can’t grab a handful and eat it.
"Empty the packet into the skimmer while the pump is running” - Okay this can be one of the BEST ways to add Stabiliser and one of the WORST.
Let’s deal with BAD first.
If you just dump the packet into your skimmer in a blob like most people will, the outside of the blob will get wet while the inside will stay dry. Believe it or not this "CAN" cause a pipe blockage that is like a concrete block inside your pipes.
If you slowly empty the packet into the skimmer box the stabilier will flow through the basket and catch in the filter to dissolve safety and then ultimately return to the pool.