I have an above ground pool with a vinyl liner. What is the difference between using granular chlorine, granular calcium hypochlorite or the chlorine tabs? It is my second full year of use, last year I used granular chlorine, but am I paying too much?

It all depends on how you dispense the chlorine. If you use a floating dispenser go with the tablet. If you have an injector attached to your pump they all would work. Never toss granular directly into the pool. It will clump and eat at your liner.