I was wondering what rating (GPH) return pump to get for my sump. I need one that is able to output 200 GPH through 3/4 of an inch pipe. it needs to lift the water about 45 inches. I am assuming that there is some kind of a math equation that you can use to figure this out but I have absolutely no idea what the answer is and I have spent around 20 minutes searching and I have yet to find any kind of a equation or answer. Some help would be greatly appreciated!