[J. T. Toad]

Eureka.

Air stones increase diffusion of air, which allow for better oxygenation of the water and movement of water as in an under-gravel filter tube. They also lesson tube blockage from calcification when the water enter and exits the tube for each bubble.

I'd get a pump and under-gravel set up. A plus to this is that you won't need the plants which can contribute their own additional debris. I'd loose the external filter (for now) as they really are good for 'chunks' in the water (filter screen) and odor (charcoal) neither of which should be a problem for, say, six months if feeding a fish to gallon ratio is correct.

I have run tanks for years with only an under-gravel and annual 10% changes of water.

The under gravel really provides a great medium for healthy bacteria and filtration through the gravel.