Anyone keep a tank with no filter?

[anythingscales]

Theres this fish store I go to in LA and some of the tanks he keeps there have no filter, just air stoned to keep the surface moving. The tanks look pretty nice, lot of growth on everthing and crystal clear water. Currently my tank right now has no filter, only a small powerhead. So far its been about 3 months, and the first 2 months it was very cloudy and brown algae covered everything. Now that Ive added some plants, the water looks very clear. Anyone have any tanks theyve kept with no filtration?

 

[Toirtis]

I have done...these are usually called 'Dutch' or 'Amano' tanks, and need to be reasonably large (usually 25 gallons or more), with tons of plants (which usually wants lots of light and CO2), and very, very few fish (ie 7 cardinal tetras and 4 algae-eating shrimp in a heavily-planted 25 gallon tank).

 

[Piscesgirl]

I have a 20 gallon long, planted, with DIY co2 that is not filtered. I do run an airstone 24/7 however. I keep 7 killifish in there and some pest snails. I do water changes of approx 20 percent a week, sometimes more. Substrate is somewhat shallow. This tank works very well for me.