Powerhead sizing

[crankbait09]

I need some assistance in sizing powerheads for my tank as well as my "cycle bin"

i have a 135 gallon tank, that will eventually house fish, as well as soft corals. how do i know how many powerheads I need, as well as how many of them. any recommendations or suggestions?

I also have a 32 gallon brute trash can that I will use to cycle my rock. what is the smallest powerhead I can place in the trash can to keep movement?

[Flippers4pups]

I haven't even unboxed them yet, but over the weekend I picked up 1 rw8 and 1 rw15 for my 125. LFS says it would be plenty. 6ft 125.