HTH Tablets with NO CYA

[waterbear]

They are cal hypo tabs that are used as part of a system. Here is the MSDS for the tablets
http://buyat.ppg.com/wercsinter/Werc...A51%3A35%27%7D

AS best as I can tell the 'chlorine extener' that they use in this sytem is NOT CYA. the MSDS lists it as a proprietary mixture in a brine soluton and their FAQ says that it combines with the chlorine to hold it in reserve and will test as combined chlorine on testing and therefore recommend testing with DPD for the actual FC. Interestng!

EDIT: They also recommend a CYA level of 80 ppm along with this system so I don't know what their 'chlorine extender' does! It seems to be something that forms CC in the water but is able to release the FC when the levels drop.