Eheim 2215 and 2217 facts and DIY performance mods.

[lescarpentier]

Dispelling a myth.

Compelled by the many contradictions on flow rates and overall lack of information available, I purchased a new Eheim 2215 and a 2217 for testing purposes.My primary intention was to test for flow rates on new filters,with and without filter media,and to see if these filters would actually produce their advertised flow rates.I also conducted tests with and without the included spray bars.Upon close examination of the filters I noticed that the impeller assemblies were identical on both of the filters except for the 2217 having a 6 blade impeller,and the 2215 having 3 blades.I then decided to test the 2215 using the 2217 impeller to overdrive it and to consequently boost the flow rate.I likewise ran a test on the 2217 using the 2215 impeller to under drive it to reduce the flow rate.As I expected,I was able to boost the flow rate significantly on the 2215 using the 2217's impeller assembly,and predictably got a corresponding reduction of the flow rate on the 2217 using the 2215's impeller.

The tests were conducted with the filters sitting on the floor with a 50 inch water height to simulate actual conditions,and tests were also conducted with the filters elevated on a 30 inch platform after I failed to match the advertised flow rates.Results were obtained by using a stop watch to measure the seconds to pump 5 gallons,and then dividing the seconds by 3600 and multiplying this figure by 5.The numbers were rounded out to the nearest 1/2 gallon. Surprisingly,elevating the filters did not improve the performance as I expected,and there was no measurable gain.However,my biggest surprise was that the output on both of the filters was the SAME,with the included Eheim filter media,and with empty canisters.

Advertised flow rates are 164 gph for the 2215,and 264 gph 2217.

Results

{2215} ---------------w/2217 impeller


141.5 gph open tube ---171.5 open tube

136 gph w/spray bar -----152.5 w/spray bar

------------------------------------------------------------------

{2217} --------------------w/2215 impeller

229 gph open tube--------- 195.5 gph open tube

202 gph w/spray bar ---------171 gph w/spray bar __________________

[dougz]

That's great, Les, thanks!

I was wondering about this very thing (flow reduction issues)..

I have 2 2217's that I'll be using for a 75g.

Do you have results for the gph for the 2217 with a 2217 impeller?

[lescarpentier]

That is it on the lower left column.


{2217}
229 gph open tube

202 gph w/spray bar

[dougz]

Whoops, missed it.. Thanks!

[kakkoii]

Thanks this is great news!