Why Isnt My Filter Working?

Hi, I have a filter set up to a 26gal tub. I picked up from a guy for free. As far as I can tell I have all the pieces. The propellor is spinning correctly and I connected everything. But water isn't being sucked up the tube. Any help?

 

Is the water level high enough? Because I found that with one of my filters, if the water level is not high enough it won't take in water.

 

I agree with Albifrons but another possible cause could be the intake is too large and you may have to do some handiwork to make it smaller

 

Hi, knowing the make & model of filter may help members advise you better, some makes of filter seem to have idiosyncrasies that require certain tweaks to get them going.

 

Is the filter primed with water in it? Is it one that needs to be primed?