In article ,
w says...

Azoo Palm filter, designed for tanks 5 gallons and under.

Another fairly low-cost solution. Pumps 2gph less than the Duetto's
lowest setting. Now if I can just find it locally :-).

This group is extremely helpful. Thanks to all who responded to this
(and to my many other questions).

--
Homo sapiens is a goal, not a description