I was so happy to find your site. I have a 15X48 intex above ground that holds approx. 3700 gallons. I've had water in it a few weeks now and mistakenly thought a puck in a float around holder would take care of chlorine needs. I read quite a bit in the school pool section and added 5 oz of 10% chlorine. Will take a reading later after the pump has been running a while. But I am still finding all this very overwhelming. Glad I started out with an above ground.