if its the same as my 180 was you'll have an durso that looks like a tap, and then a thinner return,
there noisy, sound like a toilet and generally annoying.
what i did was to turn mine into a herbie overflow.
what this involves though, is:
cutting the thicker drain pipe down about 6 inches, this lowers it in the overflow and will creat a full syphon, on this you need either a ball or a gate valve,
the thinner return pipe i cut to create an emergancy drain, on this i have an elbow so i can adjust the drain height,
the return pump then needs a new pipe, i use a return from an onld canister that returns about 1" under the waters surface,
the way you set it:
open the valve fully and set your pump on 70% ish, then close the valve and you will see the water rise in the overflow, once it gets to the emergancy overflow it will start to run down that, open the valve a little, and now use the pump control to get the emergancy drain, having just a trickle down it.
this is the quietest way.
it will need fine tuning from time to time,