I added a gallon of CS plus 1/2 gallon CCopper to my 375 gallon hot tub. At our local fair I asked the hot tub dealers if I should keep adding these ingredients. They sell a silver nitrate plus copper package called Nature2, one cartridge lasts four months. Testing for pH, alkalinity needs to be done regularly and they say to add chlorine to activate the cartridge and if bacteria gets out of hand. They said to add something else weekly to clear away dead bacteria? I thought that was the filters job.
Its pretty nice to take a hot tub and CS treatment at the same time. I hate to wash off the CS after getting out of the tub. I have been adding a cup of CS every time I get in the tub. I also added a cup of CCopper after one week. Today I adjusted the pH from 8.2 to about 7.2 by adding pH minus Brickey
