Re: Plan for sump would like input!!!!!
Let gravity do the filling as there is a greater risk of over flow and flooding if you pump the water down......You will have to have a space for the return pump big enough to allow for the hose and easy access.....I take it that you will have a skimmer box and U-tube for the outflow......Have you thought of a stop valve for the pump return hose....When the power goes off you will need something to keep the water from syphoning out of the tank..........A large synthetic open cell sponge will do a great job instead of the bio balls...........Your pump size will depend on how much current you want flowing in the tank.......The Mag pumps are good and they come in many pumping rates.
Go to a LFS and look at the commercial sump setups for marine tanks for ideas.
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