[Peter Finke]

Kindai, whom do you mean? Me? I don’t use any filters or air-pumps. Certainly, the licorice gouramis come from floating waters and they like that in the aquarium, no question. But they display and breed in my small stagnant waters, too. The only thing is that a small bubble-filter would make things a little easier for the aquarist by reducing the intervals for water-change. But it’s too noisy for me since the small tanks are part of my working studio.
And the neccessity for maintenance measures is quite diversified. Some tanks with a mass of Ceratopteris spec. will stand long-time stable and with only little germ-load, while others, mostly with less active plants, must be cared for every two weeks.