Fluval U2 U3 Powerheads

[Jjsmith46]

Can i swap the powerheads over in my u 2 and 3 will they both fit each other,im looking for more filtering from u2 and slow filtering from u3.

 

[mwood2]

If your talking about the propellers they should be compatible with each other. I placed a propeller from my Fluval 2+ into my U3 and it worked but the flow rate was not as good. From what I see the + series uses the same propellers as the U series thus the 2U and 3U should be compatible but just different flow rates.

 

[Jjsmith46]

Im gona try swapping the actual powerhead that the inpeller sits in as i think the inpellers are same size its the powerhead that gives flow rate ill try, and post my results

 

[Nick16]

why dont you just swap over the whole filters? problem solved.

 

[I Keep Fish]

why dont you just swap over the whole filters? problem solved.

Exactly, although the U3 is about 16" and the U2 is about 12" give or take i think? if the U2 is in a 24x12x12 the U3 would not fit

 

[jm_]

the propellers control the flow rate if i recall both very good. some filters have controllers to flow, so you can buy big and reduce it etc.. not sure about that but sound ok

try it and find out, or i might trade out the filters but the u3 is quite big and have 2 returns - good filters for what it is and does a tidy job

 

[OldMan47]

The flow rate is indeed a function of the design of the impeller and the casing where the impeller sits. The impeller and its pump casing work together to provide a particular flow based on both the impeller dimensions and the clearances between the impeller and its casing. If the impeller fits well into the casing for a different sized filter, it will indeed move water but its performance may not be up to the value provided by either original filter. A smaller impeller placed in a casing larger than it should be placed into will not deliver its rated flow. Instead water flow will bypass the impeller's flow path and return to the impeller inlet area. That means that the large clearances that happen when a small impeller is placed into a large pump casing will lead to a loss of flow even compared to the smaller filter. I would definitely move media to a well matched impeller and impeller casing filter than move the impeller around and lose flow capability.