I use a Tunze 1073.050. It's nice to be able to adjust the flow with a DC pump, the feed mode is nice, and battery back up capability is always a plus, but with all that said, I would buy an AC pump if I had to do it over again. With AC pumps there's no controller or cheap power supply to fail. As said above, it's the heart of the system. Save yourself some money and look at a Tunze 1073.020.