I have a red sea max e 170 and have a love hate relationship with the rear sump aoi design. My biggest gripe is that in order to alter the flow of the return pump I have to take out the sponge, unscrew the pipe, pull the pump out, adjust the know with no real indication of what each click actually changes, put it all back together turn it on and determine if the flow is good. If not what I wanted then I have to do it all over again. Is there a controllable return pump that will fit the very small return pump chamber (slightly less than 6" in length and 4" in width)?