We considered the fx4, it would fit in his cabinet, but when the space needed above the filter for hoses and valves etc was taken account of, it didn't fit. I think the FX4 is 16" ish + say 5 or 6" needed for hoses. He had 18" space. That G6 is 13" so it might have fitted. It was the weirdest aquarium cabinet, with no thought whatsoever given to canister filters (picture attached). We also considered HoB or internal filters but he didn't like the idea for some reason. He never did get back to me on what he ultimately decided on, but seemed dead set on using his FX6 as he got it cheap, so it probably got sat on the floor next to the tank with the flow turned right down.
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