main return pump on 210 gal reef tank

so I wanted to get feed back on a mag drive 9 pump as the main return pump for a dual over flow return 210 gal reef tank. My local fish store said several bad things about this choice. first not enough turn over for the size tank. Second too much heat. his suggestion was a blue line external pump. he was all so dead set against the use of any PVC plumbing in the build. He said in time I would have leaks in ball valves and then it's difficult to change out.

 

reeflo dart hybrid with some sch40 or 80 pvc and you will be fine

 

Mag 9 is too small for a 210g tank. At 6' of head the Mag 9 will get you about 700 gph of flow. You probably want closer to at least double that (if not more).

There are any number of external pumps that will meet that need. As leighton mentions a Reeflo dart will do so (about 1600 gph @ 6').

The Blueline 100 HD would give you about what you need, but draws roughly three times the power of the Dart, costs more and gives you less flow.

Go with the Dart Hybrid - Reeflo makes GREAT pumps.