We use trichlor tabs to chlorinate the pool on a daily basis (I wish we didn't but hand dosing is not allowed in a semi-public pool and money is not available for the automatic options).
I am required to use tablets with added flocculant to improve the filtering (cryptosporidium control). Last year I could buy a trichlor tablet with aluminium sulphate in it to meet that requirement. This year the only tablets that I can buy with added aluminium sulphate also contain copper sulphate - about 5% of each by weight. I am concerned about a build up of copper in the pool. I know how easy it is for CYA to get high, and it seems that copper could easily go the same way.
Each tablet adds ~2PPM of chlorine to my pool and ~1.6PPM CYA, which has now reached 50PPM. I'm sure it's possible to calculate the added copper as well, but I can't seem to work out how to get started. Can you help?
Numbers right now are typically:
We're having a problem with a small amount of free floating brown algae, probably because of the wettest British summer in living memory, which is why the CC is up. I was advised to shock the pool and then add algaecide. I still trying to work out how best to do the shock step - do I drain half the pool first because it will go a lot easier and quicker at lower CYA levels?
And I am planning to skip the algaecide step. I think there's a reasonable chance that there's already too much copper in there, and so adding more would be really bad. I don't know how to test copper levels though, and thought it might be easier to work it out. I could just skip that step regardless, but I would still like to know how much copper is in the water.
Any help or advice would really be appreciated. I think this forum is amazing and Richard Falk's Pool Equations spreadsheet even more so. I have yet to meet any pool people here who understand just what an impact the CYA has on chlorine's ability to do its job.