[Raymond S.]

An air pump for a sponge filter needs to be on 24/7. If that was not the case when you had one..clearly that was the reason it kept re-cycling. Any bio-filter must be on 24/7.
The beneficial bacteria need the Oxygen provided when water passes over it.
This would be an excelent filter for low flow and outside also. This is a site that sells the one mantioned by squatindog.
http://ca-en.hagen.com/Aquatic/Filtration/Clip-On
Amazon.com: Marina Hang-On Breeding Box, Large: Pet Supplies
Also can be use as a filter.

 

[Raymond S.]

If you want reduced flow that Marina breeder box will do it but to get more flow from an HOB it will do that better but likely more gently on an end of the tank.
Gently in the overall tank. That breeder box uses air to move the water(or a pump)
so it is slower than a regular filter and does need to be adapted for use as a filter but
just by adding filter material not physical alterations.
I now have a filter which produces a current like stirring a bowl. Used to be one like
a clock...down one end and back up the other. Liked that one better.