Starting up a filterless tank

[Tijn74]

So I recently bought a second-hand 20 gallon tank. I got all kinds of stuff with it such as 2 (rather old) filters, 2 air pumps, 2 heaters, a lot of decorations and some stuff to help your cycling proces (the bottle still had the price tag on it, in guilder, a currency which isn't used here since 2002. Not using that for that reason)
Okay anyways, I wanted to set it up as a filterless tank.
I already put some plants in and got the filters running, but how do I make it filterless?

I currently have those plants: Echinodorus, Myriophyllum, Eleocharis, Lilaeopsis and Cryptocoryne amicorum.
I have Superfish Plant Substrate on the bottom
and gravel I bought at a Local Fish Store (well a garden center with a fish section)
I read that the Walstad method is a good way to do filterless, but as far as I could find, that uses different kind of bottom soil.
So what do I have to do to get my aquarium filterless?
I'm ready to buy more plants and other stuff.

 

[the loach]

I also have a couple of filterless tanks. It is real easy... heavily planted and lightly stocked. Your tank looks nice already.
You don't need special soil, you can just use root tabs.

 

[FreshyFresh]

So what do I have to do to get my aquarium filterless?

A light bio load, water changes and keeping an eye on water parameters.

 

[JerryHarris]

To be honest, that already looks good. I agree, you'd need root tabs though.