Hello - I have an above-ground Doughboy that was just installed. A chlorinator was installed with the pool. The pool installer said to use chlorine tablets, any name brand trichlor tablet either 1" or 3". The local pool supply store said that the tablets would cause a more rapid degradation of the vinyl liner and he is pushing the granules. Is there a trade off in the life of the liner for the convenience of the tablets, or is this a commission issue? Do you have any brands that are recommended? Thanks for your help, Bob