Looks like this is what I need!? Bought my house 2yrs ago with my first pool, have been using tri-chol from Lowes since then. Previous owners "schooled me" and local pool store. Didn't realize there was a problem until a few weeks ago when I joined the forum and "schooled" myself with your info. CYA is at 110ppm! I don't want to do a half drain every year. I don't have the money to convert to SWG yet due to the $ spent on new filter and pump. I would like to continue using the clorinator for now if i can. Is this what I need in order to use the Clorinator, not have to drain anually and not have high CYA levels? The IG is vinyl and I have a new rainbow dispenser not installed yet