900 GPH is the PUMP output. A different test method. 600 GPH is the FILTER output with or without media. When the canister is clean and not jammed pack with media, there is not enough of a restriction to lower the flow rate a -300GPH. The Pump output is probably off the canister with very little restriction on the suction side and very little on the discharge side. This all changes when putting it on the canister with an intake to the impeller that is nearly 2/3 the diameter of the intake of the enclosed impeller, among other restriction.
Picture it this way, my modded fx5 filter, which could have a lot less restriction, if there was any to measure in the original design, still only flows 600 GPH.
http://innovationlandscaping.com/fx5/internalmod.html
Correct. Probably a bit lower with media, in the 750-800 GPH range since Eheim media really jam packs their canisters. You still have roughly a 12.5" - 13" diameter cylinder for water to pass through. Thats makes the area fairly large. Over 122 sq/in
Thats because 600 GPH is the filter flow output and not the pump output. Retailers are probubly noticing that the 900 GPH is for marketing only and should not have ever reached the text book manual for the Fx5.
The pump output is around 900 GPH for the Eheim 2262 pump. They just use that figure for marketing purposes. Stick this pump on a canister and with restriction on the suction side as well as the output side and you get a reduction in flow.
Thanks all doing my price searching and research today I got the day off woot. Either way I am gonna have both because as of this morning I got 2 FX5's lol and I am dead set on owning a 2262
