Hoping someone can help. We opened the pool last week (18,000 gallon pool) and started the process of balancing the chemicals. After about 4 days, the water was still cloudy so we took a sample to the pool store to get tested. High ph and high Alkalinity. Suggestion was to add muriatic acid to reduce alkalinity; said ph would drop a bit as well; also suggested soaking filter cartridge in a muriatic acid/water solution because water flow was low. Did all of that and ph ended up almost unreadable and alkalinity ended up good. Added chlorine and it disappeared in no time. Added ph up and took another sample to the pool store. High ph and slightly high alkalinity. Added ph down; ph and alkalinity readings looked good so added 1# of chlorine. No reading after an hour. Read on this thread about using regular chlorine bleach so bought some of that. Added three gallons and had no reading after about 30 minutes. Added 4 more gallons. Took a reading immediately and registered the chlorine high...waited about 5 minutes and read it again...GONE!

We don't know what to do next.