Sponge Filter Not Sucking?

So I just bought and put a sponge filter into my tank. I connected the air stone and airline tubing to it and turned on the air pump. Its bubbling like you would expect but I'm not sure if anything is sucking up through the sponge?
I bought a sponge filter rated for a 10 gallon tank even though my tank is only a 5 gallon. I connected a five gallon air pump to it. I can see stuff floating around in the water but I don't see the sponge pulling anything in. When I reach my hand in the tank and put it right next to the filter I don't feel any pull at all? Is this normal or did I somehow get a faulty filter.
This is my first time using a sponge filter but I looked up multiple videos and they all seemed to do exactly what I did. I followed all the instructions on the box so I don't think I'm doing anything wrong. I did have to cut about two inches off of the "lift tube" (the plastic tube that the airline tubing runs through) as it just a bit too tall for my tank. Is that what's wrong?

 

Hi!
Sponge filters are funny things, it seems like they're not sucking anything in, then, after a month or so, when you rinse the sponge out in a bucket of (tank) water, all this brown gunk comes out!
The best way to reassure yourself that there's 'flow', is to lift it a little bit above the water line. You'll see a stream of bubbles bubbling up and out of the tube and, of course, each bubble of air basically has a 'shell' of water around it-if you know what I mean! This is the 'lift' The bubbles are pulling the water up and out of the lift tube, that water is being replaced by water that is sucked in through the sponge.
It's very gentle, but that's exactly what makes them so good for fry, shrimp etc.
Hope this helps!

 

The sponge filter is a biological filter. It is not designed to catch all the "stuff" you see suspended in the water.

 

HI again,
I agree with MWR, the main benefit is definitely the biological filtration, but there's no doubt that they do get full of, must be microscopic, bits of gunk as the water flows through.
But, no, they don't polish the water like a power filter would do, any big(ish) bits of stuff floating in your tank will just drift on past it!

 

itsEmma Thank you so much that was super helpful

MWR Thank you for clarifying, I thought they were both a biological and mechanical filter

To either of you, does this mean I should get another filter to pick up the bigger chunks? I mainly liked the idea of a sponge filter because its a "two in one" and because of the lack of current it produces.

Also if either of you know is it okay to turn the sponge filter off for a few minutes at night or in the morning while feeding my fish or will this kill all my beneficial bacteria? I imagine it would be okay because I will have to turn it off for water changes correct?

Thanks so much to both of you

 

Yeah I have a double sponge filter in my 5 gallon shrimp tank, it wasn’t cutting it. So I added a small cheap azoo hob and now it’s so much better. It’s fine to turn it off during quick feeding times, just don’t forget it!

 

HI again!
I agree with WTFish, a small 'normal' filter of some description will take care of the mechanical filtration. It depends how perfectly clear you want your water to be. I have little internal cannister filters in my shrimp tanks (no idea of the brand, they came 'free' with the tanks-that's how small they are!) as well as the Sponges.

I did just use the Sponges exclusively for quite a while but all the little particles floating around started to annoy me so I popped the free filters in too.

You don't say what's actually in your tank, if it's small, you'll want to cover the intakes of the power filter with a bit of floss/net or something to make sure babies don't get sucked into it.

And finally, just as WTFish said, sponges are fine to turn off for a while-and it's nice because, unlike normal filters, they don't release a cloud of gunk back into the water when you do so or go to lift them out!
Hope this helps!