I have a 20 Gal
tank I got from PetSmart on sale. It was their Great choice brand 20 Gal
starter set, which came with a cheap internal filter and hood/light kit. I got it because the tank and hood seemed as good as any other brand they had in stock and it was only about $40.00 so everything else was disposable in my mind. I got a fluval AC30, so I didn't need the internal filter, but saved it because I might use it somewhere else or give it to one of my daughters to use.
Well after about a month of live fish in the tank I cleaned the gravel and with a syphon vacuum and did my water change and had lots of mess floating in the tank. So I went and got the GC in tank filter out of the box to stick in the tank temporarily, and it was fairly large. I did not like this. However, when I got all the parts out of the box, there was a small submersible "power head" that got attached to the bottom of the filter to pump the water into the filter.
I got right to work and built a small HOB
bracket for the power head and used an old filter tube, a tube from an under ground filter and one of those charcoal filter adapters (sans charcoal) and made myself a much more discrete particle filter. I just was a little filter floss material in the tube and in about two hours my water is crystal clear again.
So just for kicks I went back to pet smart to check out the price of power heads, and I think the cheapest one was around $30.00. The price of this filter, about $14.00.
Not saying the quality or longevity of this is the same as real power head, but if you just need to move some water, or in my case a part time filter, it will do the trick.
I included some pictures but the camera on my tablet is not the greatest and my fish love to swim right in front of me, so his tail is at the top of one picture. but you should get the idea.