Hey guys I'm looking for a cheap pump to pull water out of the tank. I already have a mixing station to get new water into my display tank. Now I just need something that has a 1/2" connection to connect to my Python and suck 20 gallons out of the tank every time I do a water change. I have an extra pump but realized it only has a connection to push water. I need something that will pull water. Thanks in advance!