type of water pump?

I've noticed there are pressure rated pumps and non-pressure rated pumps. What's the difference?

I was reading about someone's aquarium and they wanted a pressure rated pump for the closed-loop. Is one type of pump better than another whether it's used for a sump return or for a closed-loop?

 

Pressure rated pumps are built with backpressure in mind. They perform better than a normal pump under high head loss, and when pumping through large numbers of elbows.

 

do you think if I don't expect a lot of elbows or bends, and if there's a low head loss, is it a pretty trivial thing to worry about?

 

Long runs of pipe cause head pressure plus some skimmers work better with pressure rated pumps. Unless you are coming for a basement on a 55g then you don't need a pressure rated pump for you system.

 

you could always get a pump that can outperform what you need and just restrict the flow. its better to be safe than sorry.

 

Thanks for the comments! I think I understand a bit better now, although it kinda makes sense when you really think about it. ;D