#11199 Orcia River, Castiglione d’Orcia, Siena, Tuscany, Italy

Aquarium information

Aquarium description

Set-up date

3 February, 2026

Aquarium decoration

To faithfully recreate the wild landscape of the Castiglione d’Orcia gorges, this aquarium was designed according to strict ecological and hydrodynamic principles, avoiding purely decorative composition. Each element was positioned according to a fundamental question: How would this structure naturally form under the influence of water flow and geological processes?

Rocky hardscape (limestone gorge):
Only limestone and sedimentary rocks with the warm grey tones characteristic of the Castiglione d’Orcia cliffs were selected. The layout represents a realistic cross-section of the river environment.

A large rock formation dominates the left side of the aquarium, simulating a cliff face shaped by erosion and seasonal flood events. On the right side, the arrangement gradually rises to recreate a natural riverbank or sloping margin. The central area represents the active stream channel, forming an open flow corridor that crosses the aquarium vertically and creates deep crevices and sheltered zones for benthic organisms.

This structure reflects the natural interaction between geology, current dynamics, and habitat formation observed in the Orcia River gorge ecosystem.

Aquarium equipment

Filtration: DIY 20 L internal filter system combined with aquaponic filtration.

Fish care

The Orcia River represents a highly oxygenated freshwater environment, and many of its native fish species are rheophilic, adapted to life in flowing water. To replicate these natural conditions and encourage appropriate behaviour, strong and continuous water movement is maintained throughout the aquarium.

The return pump flow is periodically adjusted, and the outlets are regularly cleaned to ensure efficient circulation. This creates a constantly moving, oxygen-rich environment that promotes active swimming behaviour and supports the physiological condition and muscle development of flow-adapted fish.

Fish:

• Alburnus arborella (Leuciscidae) – 17
• Padogobius nigricans (Oxudercidae) – 3

Crustacean:

• Atyaephyra desmarestii (Atyidae) – 6

Mollusc:

• Radix balthica (Lymnaeidae) – 20

Plant care

I only prune the roots of the plants in the aquaponics system.

Aquatic plant:

• Ceratophyllum demersum (Ceratophyllaceae) – 10

Aquatic moss:

• Fontinalis antipyretica (Fontinalaceae) – 10

Wetland plants:

• Mentha aquatica (Lamiaceae) – 20
• Phragmites australis (Poaceae) – 20

Water care

Maintaining the minimum water level and topping up evaporated water when necessary.

Dimensions

Length

120 cm

Depth

60 cm

High

50 cm

Volume

360 L