The phenomenon of fishless aquariums
F. MattierShare
The concept of aquariums without fish would have seemed quite strange, even paradoxical, just a few years ago.
But more and more enthusiasts are now turning to this passion.
Of course, the awareness of animal well-being plays a role in this change — a movement greatly strengthened by all the reflections around fish well-being.
There is also criticism of the fish trade, whose ethics can be questioned: fish imported with inevitable death during transport, poorly controlled farms set up in Eastern Europe or worse, wild fish taken from their natural environment, additional death in points of sale…
Topics that recall the issues related to goldfish:
– put an end to goldfish indoors
– the goldfish scandal

But many aquarium keepers also discover, over the years, the charm of aquariums without fish.
The absence of fish is often the condition to set up a true stable aquatic ecosystem. Where, in nature, there is generally less than one fish per cubic meter of water (1000 liters!), the density in an aquarium is much higher and changes everything. Our fish spend their days inspecting every square centimeter of their aquarium, making it impossible for the micro-fauna to establish. The biological cycle is thus broken by the omnipresence of these little hungry predators! This is especially visible with lively species like the Platy Variatus.

Without fish, it becomes possible to focus on the micro-fauna and plants, which together establish a complete and stable cycle. The critters (daphnia, worms, hydras, water lice, ostracods, etc.) feed on bacteria and waste, their droppings feed the plants, whose dead leaves feed the bacteria, and the cycle is complete…
The closed loop is practically possible.
One then has an aquarium without chores! No need for a filter or aerator, heating is generally unnecessary, no fish to feed, plants grow on their own thanks to the light, and the critters multiply at their own pace.
An aquatic garden, with its sole lighting, shaded and colored by the plants, is a magnificent sight. Just as hypnotic and calming as an aquarium with fish.
One meditates silently and peacefully there, the show changes according to the growth of this or that plant, and the magnifying glass placed nearby allows one to delight in the fascinating life of the critters living there. The jerky swimming of the daphnia, the hypnotic dance of the Blackworms, the water lice forming their pairs, the gatherings of ostracods on the smallest dead leaf…
No longer need a large volume, in which a fish will always seem captive: sixty liters is a vast world for such a small water louse, and even more so for a motionless plant!
The plants produce the oxygen that the critters breathe, then consume the CO2 they release, to make oxygen again. The loop is closed.
Light is the only engine of this small silent world, mostly independent of you.
And so exemplary for teaching children what nature is!
To deepen topics related to the real needs of fish, you can explore:
– the key to fish breeding
– which volume to choose for an aquarium
– which temperature to choose for an aquarium
– can fish safely eat tubifex?
– do fish sleep?
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Photo credits: Laila from Pixabay




8 comments
Bonjour,
C’est effectivement une autre aquariophilie tout aussi passionnante.
Assurément, dès que la place se libérera, j’y viendrai ne serait-ce qu’en souvenir des heures passées enfant le nez dans un ruisseau.
Bravo!
Un aquarium en circuit fermé, qui reproduit le cycle de la nature, c’est magnifique et exemplaire!
( Attention ci dessous, vous avez écrit “approvés”)
J’ai encore beaucoup de bacs avec des poissons, mais depuis peu j’ai quelques bacs avec uniquement ces petits animaux. Et je passe des heures derrière la loupe du smartphone.
Bien écrit !
Merci