i had the same sinario....i went to hardware store and got some fittings. hose, grey T, two ball valves, thread to barbed grey pieces, and some hose clamps, and some pvc
to make a U for to go over the edge of the tank. i chose not to use glue because i didnt know if it was safe.
so you split the output of the canister...put a ball valve on each end, one goes to the tank and one goes to the UV
then the tank.
i keep the valve going into the tank open 100% and adjusted the flow into the UV
to about 60 gal
/hr. (fill a one gallon container, time it and do the math)