You can have it to the side thats no problem.
Its best to have both hoses the same length.
If that doesn't work I normally make the drain hose the longer one and the return the shorter, since the canister relies being pressurized. the return pump theoretically runs at close zero head since the siphoning water is creating pressure that helps negate the suction of the pump, and thus helps the pump push water. Having a shorter distance for the returning water to travel always helps, the siphon is basically "free" energy. That's how I understand it anyway.
Make sure also there are no loops or bends in the return hose that dip lower than the canister or the canisters pump. It will kill your flow.
Ive never owned an fx6, just a 406 and some smaller cousins, maybe someone who has owned this particular filter can chime in.
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