Fluval U3 Filter Question

[philak]

I've been cleaning the tank so have some small bits of plant debris floating around at various levels. Although the output from the filter ( set for the central spray bar ) appears to be strong and creates a good current around the tank i have noticed that debris doesn't get sucked into the side filter sponges as i would expect. It just goes past the filter and continues to circulate.

On taking the motor head off the bottom of the filter i can see that water appears to be drawn in through the lower outlet (if using the spraybar setting) , goes up through the biomax cage inside and out through the spray jets. I assume if you change the settings to the bottom output then water is drawn in the reverse direction from the top outlet ,down through the biomax central cage then out the bottom.

In each case though water is only being forced through the core of the filter ,ie the biomax cage. There appears to be no force other than a slight venturi effect that drags water through the filter sponge on the outsides? Am i correct in this?

Cheers
Phil

 

[Keithoms]

I've been cleaning the tank so have some small bits of plant debris floating around at various levels. Although the output from the filter ( set for the central spray bar ) appears to be strong and creates a good current around the tank i have noticed that debris doesn't get sucked into the side filter sponges as i would expect. It just goes past the filter and continues to circulate.

On taking the motor head off the bottom of the filter i can see that water appears to be drawn in through the lower outlet (if using the spraybar setting) , goes up through the biomax cage inside and out through the spray jets. I assume if you change the settings to the bottom output then water is drawn in the reverse direction from the top outlet ,down through the biomax central cage then out the bottom.

In each case though water is only being forced through the core of the filter ,ie the biomax cage. There appears to be no force other than a slight venturi effect that drags water through the filter sponge on the outsides? Am i correct in this?

Cheers
Phil

Annoyingly, sounds about right. In my first tank i have a fluval 2+ running, it is fantastic for picking up debris and can clear a tank very well with alot of force. When i picked up my new tank i decided to get the new U2 for it. It does pick up some stuff, and flow around the tank is good, but its really not great at the debris. And when im trying to cycle it using a mature sponge, if its not getting enough water movement through it, its going to be hard to cycle this biomax.