15 gal flex

[Ketchem]

I am new here and I have a new 15 gal fluval flex bow front. After it has been running a while the water level in the pump section is about 1 1/2” lower that the front. why and is that normal ?

 

[Uberhoust]

I don't know about the filter in question but if the pump is pumping water out of the filter side the large discrepancy suggests that the intake is partially plugged. The Fluval filters I believe have a foam pre filter, which likely needs to be rinsed out. If this is the case take some aquarium water and squeeze the prefilter foam in the water a number of times until you minimize the amount of brown material leaving the foam. Be cautious as the foam prefilters are kind of delicate.

 

[BrianK]

It will always be slightly lower but more than about an inch means the foam in the filter section or the pre-filter (if using) is clogged a bit.