Remove the aquarium filter: what if it were possible?
More and more enthusiasts are rediscovering a simpler aquarium hobby by doing without a filter.
In the early 2000s, the success of the poubellarium represented a subtle yet profound break in aquarium knowledge.
"Some enthusiasts have started to take their fish out to the garden for the summer, in simple plastic bins or rainwater collectors! The idea was to offer them a bit of real wild life after a winter in an aquarium, less stress and a feeling of captivity."
No heating (and therefore irregular temperatures), no ventilation, no filter... nothing met the standards of aquaristics.
Yet, against all odds, it was observed that fish often developed much better and were healthier in these rather... surprising conditions!
For the most seasoned aquarists, it was a mystery, with some even struggling to believe what they were witnessing.
But the essential question, and the most debated even today, was: how could these tanks operate without any filter, while our aquariums always have one?
The first reactions, reluctantly, were to concede that it could work "provided there are very few fish".
But, once again, the experience showed the opposite. Especially since some had already taken the plunge and also removed the filter from their aquarium... without any unfortunate consequences!
"While an aquarium is sold with its filter, how could such a thing be possible?"
"Aquarium filters are attributed two functions."
- a mechanical function (remove particles and impurities from the aquarium)
- and a biological function (degrading waste and ensuring the nitrogen cycle).
In the absence of a filter, the first function is no longer guaranteed.
Waste settles on the bottom instead of piling up in the filtering materials. As it does in nature.
On the other hand, the biological function is perfectly ensured without a filter.
It doesn't need one at all. Like in nature, the entire aquatic environment is a very rich microbiome, and bacteria populate it by the billions, both in the water and on the walls, plants, soil... Every grain of sand is coated with a bacterial film made up of countless microorganisms.
Thus, an aquarium rich enough in microbial diversity is a filter in itself.
These bacteria ensure all biological cycles, including the famous nitrogen cycle.
This cycle generally consists of transforming organic matter into nitrites, then into nitrates (less harmful). And this can be done with or without a filter, it works just as well!
On the other hand, believing that the filter would do more than that (for example, reduce the nitrate levels) is a stubborn belief...
With or without a filter, the amount of nitrates in an aquarium is exactly the same. Only plants can make them disappear by consuming them.
The stronger the light intensity, the more intensely they will do it.
This explains why the measurements taken in planted poubellariums revealed surprisingly low nitrate levels. And this without a filter.
There again, as in nature.
On the other hand, it is true that the mechanical role of the filter helps to prevent deposits on the bottom that some might find unsightly, by sucking in and retaining suspended particles. But a simple siphoning of the bottom two or three times a year is enough to solve this problem, which is ultimately just aesthetic.
To do without a filter, it is therefore enough to allow a maximum microbial diversity to settle.
This is the role of the Zollabox startup which provides an aquarium or a poubellarium, or even a pond, with the millions of microbial species included in its three doses (and not a cloned strain!), thus forming a rich entourage that is so precious for aquatic balance, a maximum biodiversity.
There is no doubt that we are on the verge of important discoveries regarding this aquatic microbiota, about which research is still in its infancy.
Extreme cleanliness is the enemy of the aquarium!
The other advantage of doing without a filter is that it eliminates the current and the suction that can disturb certain species. This current should even be absolutely avoided in fishless aquariums populated with aquatic microfauna and plants. A filter would then suck up your ostracods, your daphnia, your Blackworm, and sometimes even the water lice that are, after all, the main interest of these highly sought-after and tranquil meditation aquariums.
The old "under sand" filters, connected to a simple small air pump and which created an imperceptible current by just passing water through the substrate, already utilized this ability of the aquarium to use its own microbiome to stay healthy!
Then came the era of technology at all costs.
Sometimes to the absurd...
To learn more about natural aquaristics, don't forget the Mattier blog.
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