Hello everyone. I purchased a home months back with an I ground 17x30 pool. The pool has always been maintained be a pool company. This is the first time opening the pool since I've owned it. I paid a pool company to do it so I can learn. My main questions are what and how do I know when to add chemicals. They added 5 gallons of chlorine and a gallon. I had a couple 3 inch chlorine tablets left over from when I purchased the house so he threw the 3 tablets in the auto feeder. What chemicals will I need and how do I take care of this pool? The pool company was not that helpful because they wanted me to use their service. Thank you for an advise given