Rivers, where the water flows so fast that it polishes gravelly channels and leaves remain only as fleeting splashes of color, are among the most demanding habitats for aquarium inhabitants. Macroscopic aquatic plants are rare in these fast-flowing zones : The strong current sweeps away seedlings, the substrate is constantly in motion, and the dense canopy of tropical shores shades the stream. We recreate precisely this habitat in the 70-liter Nano Tank —an aquarium without plants , but with a diverse hardscape.

The decision to forgo greenery was a conscious one: We want to show how to set up a Dennerle Nano Aquarium so that future inhabitants such as fan shrimp or current gobies feel at home - even if (or precisely because) no roots can find a hold in the substrate.

What does a riverbed look like?

It features a dynamic stone structure, along which a slender root nestles. Amber-colored sand mimics the riverbed; scattered sea almond leaves and alder cones add natural accents and provide gentle humic substances. Everything appears as if a strong current had just passed by.

Was du für dieses Aquarium brauchst

Nano Tank Plant Pro

From 199,99 €

Product Sheet

Catappa Leaves

From 7,49 €

Black Cones

7,49 €

Nano Catappa Barks

7,49 €

Natural Gravel Mekong, 0,1-1,4 mm

From 7,99 € (15,98 € kg)

Clear Water Elixir

From 12,99 € (51,96 € l)

Alternative installation of the Corner Filter

Viewed from the side, you can see theDennerle Corner Filter 100, hidden behind the stones. The inclined outlet directs the water jet parallel to the substrate, creating a uniform, broad current – perfect for future current specialists and ideal for keeping food particles suspended.

Die Pflege

Water change
Week 1 – 3: Replace ≈ 50% once a week to flush out any initial cloudiness.
From week 4: ≈ 25% per week is sufficient.

fertilization
Since there are no plants, no additional nutrients are required. Humic substances are provided by the foliage; they stabilize the pH and protect the mucous membranes of future animals.

Current & Oxygen
Set the Corner Filter 100 to maximum performance. Make sure the outlet remains clear; check the sponge every two weeks and rinse it in the aquarium's own water to avoid throttling the flow.

Decor care
Sea almond leaves and alder cones can remain in the basin until they are visibly decomposed; then simply replace them. This ensures a continuous supply of humic acids – just like in a natural riverbed.

Light
Although photosynthesis does not need to take place, we recommend moderate lighting (6 h) so that the stone build-up can be easily observed and biofilm can form more easily for future filter feeders.