I was told I need to add 45lbs of hardness plus to my pool and 8 lbs of conditoner. We have only lived in this house for 2 years. Pool was already there when we moved in. This is the first time I have been told anything about calcium hardness so not sure what to do. I had read somewhere it was not necessary for vinyl pools. Here are my readings:

Free Chlorine 3
Calcium Hardness 120
Cyanuric Acid 0
Total Alkalinity 80
ph 7.8
Copper 0
Iron 0
Phosphates 500

The pool is an in-ground. Apprx. 28,000 gallons with a vinyl liner. Please help!

Thanks in advance!