Packaged pool chemicals

Chlorine stabiliser runs your pool. It is the single most important chemical level to be able test for and dip strips can’t accurately test it.
The vanishing dot type test is in expensive and good enough for most people’s needs.

Packaged pool chemicals Multi action galetts, lent and choc all contain chlorine stabiliser (cyanuric acid CYA)
Cheaper galetts are usually dichlor, the more expensive are trichlor, that means adding 2 part chlorine (Di) or 3 parts (tri) this means, For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, (HTH chlorine sticks usually) it also increases Calcium Hardness (CH) by at least 7 ppm
You need some CYA to protect the chlorine from being burned up by the sun, the usual level required is 30-50ppm.

I use DPD for chlorine and a calibrated pH meter, with a phenol red confirmation every few days. I use aquachek 7 strips for alkalinity and CYA, which I know aren’t that accurate but they give a good indication if the CYA is getting too high. I do use chlore lent tablets, but also liquid javel so the CYA levels don’t get too high.

What would you recommend as a more reliable CYA test?

The vanishing dot type are fine.
I may have mentioned pools I have tested with CYA at 180 & 200 but customers strips 30-50!

All the clients we work for (that have pools) insist on buying the chemicals themselves which are either sourced from the nearest supermarket or Cash Piscines.

Mmm… that must make it a bit hit-and-miss doesn’t it ?? leaving you to carry the can if the pool isn’t up to muster…:pensive::pensive: