Reverse Undergravel Filter with an additional powerhead for circulation.
This tank receives daily doses of PMDD; .5 ml KNO3 solution and .25 ml of trace element solution. I've got the filter setup to be continually amending the substrate with the wastes in the tank as well to provide the rich substrate which the crypts need.
This aquarium is a biotope of a highland tributary of the Mahaweli River near the city of Kandy, Sri Lanka. The effect I was trying to recreate was that of a shallow streamlet cutting through the rainforest. Fitting in with that theme I chose the Cherry Barbs and Mountain Loaches as they are both less obtrusive and more peaceful than the Black Ruby Barbs which are also native to that area.
The aquascape was designed to ultimately allow the large plants to grow up and shade the lower portions of the tank while giving room for the short plants to overgrow the substrate, especially the front/center portions. The two species are starting to blend boundaries very nicely at this point with runners poking up in sections previously established for/by the other species.