Jason,
Thanks for the link, but I had already been to their website. Unfortunately, the flow chart that they have pictured for the SEN 500 is actually the chart for the SEN Mini 55 pump. Plus they don't give the dimensions for the pumps. They have the flow chart for the SEN 300, which helps. But I was leaning toward a 500 GPH pump. I thought they may have provided you with some figures or that there might be info in or on the box.
For the price and the lower wattage, I think I would go with the SEN 500 over a Mag 5 if it isn't a lot bigger and the flow is similar at 4 ft of head. Is there any info in or on the box, and can you give me some general info at to the size of the SEN 500 vs the Mag 5.
Thanks again,
Ron