Aqueon Filter users

I have an Aqueon Quietflow 20.. My question is does beneficial bacteria live on the bio-holster ? Thanks in advance

I'm not familiar with that brand of filter but basically the beneficial filter bacteria live on any hard surface that has oxygen rich water moving over it. Most of the bacteria lives in and on sponges and filter pads but there will be some on plastic filter components.

Colin_T. here is a picture of the bio-holster . would you say BB live on this plastic blue thing.

If the blue bio-holster is exposed to aquarium water, then filter bacteria will settle on it and grow. However, a sponge in the filter will hold more bacteria due to a larger surface area. So if you have a sponge in the filter or on the intake tube, more bacteria will live on the sponges compared to the bio-holster.