As with pumps & filters, you may decide to use an aftermarket (non-Intex) chlorinator from in-ground or hard walled above ground pools with your Intex pool. These units can be quite expensive, but they do provide some convenient features that the Intex models lack. For example, most of these models keep their program after a power outage. They also allow you to select run times in increments smaller than one hour, and they also allow you to select the time of day that they run.