I use a 500 GPH pump as well but I also go through several connectors a year because they seem to crack, the old Pythons were the best, never had any issues from them. So now I have spare connectors because last time it cracked during filling up around midnight when no one was open so had to drain water from the 265 to the 500 to even it out till the morning.
I like my aqueon but the quality of the plastic is awful. The valve lever on the supply side broke quickly on mine. Im considering just making a nice one out of garden hose connectors and a real hose.