Design biological filtration

"Hi 😊
Just to share our experience with you, at the very beginning (a few years ago) we had a filtration (block) but it was not our thing.
For 3 years we have opted for natural filtration, we have glued a glass plate in a corner of the aquarium and put sand and gravel as well as plants.
We just have a tiny tiny little pump that sends the water through the filtration at the bottom, and the water comes up, filtering through the gravel, then smaller gravel, and finally sand on the surface. This method completely crushes all residues such as feces, pellets ... and even eggs (we don't even bother to remove them all at once!)
It has also been 3 years since we no longer have to make water changes or clean the filtration. The aquarium parameters have also been excellent for 3 years, we have never had a problem, a peak in nitrites, nitrates .... The axolotls are in excellent health, we have never had any worms or mycoses , no losses, no aggressiveness.
In short, for us this filtration is a success, the water cascades from the top, which means that we also have no problem with stagnant water. We just wanted to show some that it's really easy to set up and it's really great to know that all the parameters remain excellent 3 years after the start of this method! Especially since we use very little floor space to leave them as much space as possible 😊 "

  1. Leave enough room for a PVC elbow laid flat on the bottom.

  2. Pebble or stone of at least 50 mm.

  3. Gravel 30/40 mm.

  4. Porous gravel 10/20 mm type Pozzolana .

  5. Unsifted Loire sand.

  6. Distance between the side and the plate between 20 and 25 mm.


To switch from its classic filtration (with pump) to this one, it is necessary to rinse and wring out the filter media (brown juice) which contain the bacteria on the gravel and the sand. These bacteria will lodge in the pozzolana which will colonize quickly. And don't change the aquarium water of course