hello please can someone help me i am wanting to buy a maxi doser to change approx 4L per day for my system i understand i can buy the stand alone version but is this possible to shut off my current auto topup while it takes 4 litres from my sump and then replaces it? . or if not which computer would i need to isolate this off during awc and what other accessories would i require to do this. My initial thoughts was i could pull water from my first section in the sump while at the same time pumping water back into my return section so not affecting the level in my sump but if one motor failed during this process then i would have issues