Fluval C2 C3 C4 flowrate difference

[stereo]

Anybody know why fluval c2 c3 c4 using same motor specs yet can achieve difference flowrate?

C2 C3 C4 all 50hz n 5w

Fluval C3 Power Filter, up to 50 US Gal (190 L)

Fluval C-Series is the world's first and only 5-Stage clip-on power filter that offers two mechanical phases, a chemical phase and a two biological phases for amazing water clarity.

www.fluvalaquatics.com

Under specs tab

Fluval filter casing can determine the flowrate too? Using same motor?

 

[deeda]

After a quick search, the intake tubes on the C2/C3 are the same size but the impeller part # is different. The C4 uses a different intake tube and an impeller with more vanes. The filter housings are also different between the 3 models.

Just a quick guess is that the different combinations of impeller size, number of vanes, maybe intake diameter and housing capacity affect the GPH of the filter. It's early for me so I may have got some info wrong. ?