210 gallon, 2 hystrix, 8 geo redheads and 3 surinamensis. Stick with the twin fx5's or 45 gallon sump? Would a 45 long with twin overflows and dual returns from a marineland 5500 be enough to even filter the tank properly? I have an idea in my head to build a sump that has mechanical filtration into a moving media bio chamber to a wet dry trickle. Loads of bio filter and filter pads placed thought the sump. Also thought of running a hob sort of refuge I saw at the Los ran by air pumps and fill them with plants?