Clear Balance

[chem geek]

The CYA can drop over the winter from rain overflow (it can do that in the summer as well if you have rain in the summer) and it can drop from bacterial degradation of CYA if you let your pool go over the winter (i.e. if you don't chlorinate it). The problem with the bacterial degradation of CYA is that it can sometimes degrade it to ammonia which would create a huge chlorine demand upon opening. If one is lucky, it degrades to nitrogen gas (or nitrate) and you don't have a problem upon opening.

For every 10 ppm Free Chlorine (FC) added by Trichlor tabs, it also increases Cyanuric Acid (CYA) by 6 ppm. So if you were using 2 ppm FC per day, then that would add around 36 ppm CYA per month from the tabs. If you shock weekly with unstabilized chlorine, then you'd use fewer tabs so the CYA would build up more slowly. If you use less than 2 ppm FC per day (say because the pool isn't in full sun or a cover is used), then you'd build up the CYA more slowly.

Though your strips might be measuring something accurate, they might not and seeing a video doesn't mean anything. Strips can sometimes measure correctly and other times measure incorrectly, especially for CYA (they tend to be OK with things like pH). For sure they don't measure to within 10 or 15 ppm which is what you can do with the CYA test using the viewing tube.

What chart are you looking for regarding using chlorinating liquid or bleach? You can use PoolMath to calculate dosages and you use the Chlorine / CYA Chart to see what minimum FC level you need for your CYA level.

 

[JasonLion]

Sometimes CYA vanishes over the winter. We believe it has to do with a certain kind of soil bacteria growing in the water, but no one has been able to get it to happen on demand. It might happen, it might not, even in pools where it has happened before.

The only two reliable ways to lower CYA are to replace water, or in select areas reverse osmosis treatments are available which lower CYA along with everything else.

The CYA test strips tend to be wildly wrong sometimes. They can work sometimes, and not work other times. You should not trust them.

PoolMath will do calculations for liquid chlorine, as well as most other forms of chlorine.

 

[iceman681]

all this makes way more since. I will have to play with the pool math more. i tried it once and didnt quite understand it. but know what im looking at. thanks for all the help.