#5788 Shallow grassy area at Mariager, Mariager Fjord

Aquarium information

Aquarium description

Set-up date

May, 2022

Aquarium decoration

All stones are locally collected in the Mariager Fjord, at the very spot, where I also was catching the fish. A few of the stones still have that layer of algae that dominates most of the stones in the fjord. The plants are also locally collected, just next to the stones.

The substrate I had to recreate by using two different types of sand. I was not able to use the substrate from the fjord, since this was simply too dirty and dusty. I have only used small amounts of silt, also collected locally.

Furthermore I have used a couple of old shells, which is also represented in the habitat.
I have not used any driftwood, since this is only rarely seen in the fjord. It is often carried on to the coast by waves.

Aquarium equipment

Filtration: black Hamburger Matten Filter, powered by a Pico 1150 powerhead. The light is dimmed LED, to recreate the rather doll light conditions in the fjord.

Fish care

This setup is relatively complicated because of the conditions in the fjord. Mariager Fjord has a lower average temperature than the typical aquarium. Danish inlets only rarely reach temperatures higher than 25°C. However, the shallow water areas are an exception, since these can reach a few degrees higher during the summertime. Nevertheless the setup requires very frequent water changes with cold water to keep the temperature in balance – especially with summer temperatures close to 30°C (even indoor).

Furthermore the setup is complicated even more by the fact that Mariager Fjord is brackish. Therefor the water, that comes with the frequent water changes, needs to have the right amount of salt to stabilize the salinity of the aquarium.

Fishes:

• Gasterosteus aculeatus (Gasterosteidae)
• Pomatoschistus microps (Gobiidae)

Plant care

The plants of the tank is Ruppia maritima and they do not need any special treatment. Ruppia maritima is a very strong plant, which all of the few plants thriving in Mariager Fjord also needs to be, since it is a quite hostile environment for any plant.

Plants:

• Ruppia maritima (Ruppiaceae)

Water care

20% of the water in the aquarium is changed every two days. Furthermore I am using a refractometer to help dose the salt correctly.

Dimensions

Length

80 cm

Depth

35 cm

High

35 cm

Volume

98 L