I had a spa pump that was designed for salt water for over 20 years. It was very reliable, quite, more energy efficient than most aquarium pumps. 3000GPH at 6' of head using 150watts partialy restricted, ss it was too much flow for my sump. It was used (5 years old maybe more) when I got it with my tank and still working great when I got rid of that tank. I did replace the seal twice in the time I used it. The only reason I did not keep it is I wanted a bigger sump on my new setup, so went with a more compact internal pump. I think it was a W.M. Lim pump if I remember correctly. I would definitely recommend them if you want an external pump.