I am having problems with running this ps in my sump. First, I think it will overflow if I leave it running more than 30 seconds. It fills up with water super fast, even in the collection cup. Second, it is comepeting for water with the return pump..... My sump is only 16 gallons, so I am a little worried here. Im scared to raise the water level to much, because I might get an overflow. This is my first sump, so any help will be greatly appreciated.