pred8er

Hello All, I am a owner of an indoor pool which came with the house i just purchased. I have not owned a pool before however I am slowly getting into reading about maintaining the pool myself instead of just having someone else do it for me. A friend of mine suggested that I simply drop in 1 bag of shock weekly in order to keep it clean and running smoothly. He also has an indoor pool and this is all he does. Would doing this on a weekly basis be enough to keep everything OK? Or should I also be using chlorine tablets? I have a heater that warms the water (common?) and I have read somewhere that using a chlorine dispenser can damage the heater elements - is this true? Thanks all. fyi the pool is 20,000 gallons. The pool is fairly long but the deepest area is around 6.5 - 7ft deep only.