one big return pump split off, or little pump with closed loop? which one is better?

[gfk]

i want to use a mag 9.5 for a return on a 29 gallon and just split it and Y off the splits. what is the advantage of using a closed loop instead of just having a bigger return pump thats split off?

[wantahealthytank]

THe only thing I can think of is if one pump goes out, you still have water movement in the tank. I have a larger tank, but went with two smaller pumps in the basement to have one still working if one dies.

Also, with the closed loop you won't be sending extra water splashing into your sump. With the big pump you will all of the circulated water entering your sump.

Other then that I really don't see much of a difference.