The manual for the pump/filter is the one which says not recommended for the 6110/6120 SWCG. I am not sure if it is the flow or some other reason. The initial pump which came with the pool is rated for 1000 GPH and the sand filter is 1600 GPH. We had planned on a larger pool next year and bought this as the original pump and filter combo is a pain having to change/clean filters every one to two weeks.