Ditto the bio wheel / nitrate factory. If you go skimmerless, then you could do *only* water changes, tho' I'd do large ones. (3 to 5 gal
Some folks believe it is possible to overskim, but I'm not one of them
. I bet if you did a search across AA on "overskimming" you'd get a few opinions.
I thought of another inexpensive option, look for a (perhaps used) Aqua Clear 300 or Aqua Clear 500 and run charcoal and/or macro algae in the reservoir. This would "skim" but it would provide more than enough water circulation without needing any powerheads and would give you a space to put some calpura ...