bam Easy level

Unnamed forest stream in south Sarawak, Borneo

Sponsored by

Malaysia, Borneo, Sarawak

I’ve wanted a long time ago an aquarium in “bornean” blackwater theme. I selected my favorite fishes, these fish are Sundadanio axelrodi and Sphaerichthys osphromenoides. I have been looking for peaceful and compatible tank mates for these fish. These fish also live in black water forest stream. Because I tried their similarly arranged aquarium.

Submitted by
Gábor Juhász-Tóth
Approved by
Heok Hee Ng & Greg Martin
Geographical region
Southeastern Asia
Drainage Basin
River catchment
Water body type
Water body name
Water body part
Water body course
Water body: tributary of
Tributary name

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Black water
Water transparency
Concentration of sediments
Water temperature
22-28 °C
Water flow/curent

Chemical parameters

Dissolved Oxygen

Aquarium information

Aquarium description

Set-up date
September, 2022
Aquarium decoration

The tank mimics a slow moving forest stream, so I used large roots at the front of the tank and smaller ones at the back with black foil in the background. I have left the barks on the roots and have hung common fern leaves in the water for a more natural effect and these mimic the depth of the harsh landscape.

The soil is boiled peat with small roots and branches. As this habitat is a forest stream, I used cattapa and fern leaves on the ground, these things are a good hiding place for all fish. The microorganisms that multiply on them are a good food source for fish. All aquarium furnishings have been heat treated for fish safety. I have used only one underwater plant species, this is Cryptocoryne ciliata because it is the most common species in Sarawak.

Aquarium equipment
  • Lighting: 2×0,95 meters IP65 6.500 KELVIN led modul 3db led 12V, 1,5W + Aquael leddy smart 2 plant 6w.
  • Heating: none.
  • Filtering: DIY side shelf filter (separeted the aquarium 10x40x35 cm) with tm20 and 30 foam, 250l/h powerhead.
Fish care

I think the aquarium recreates the ideal habitat for:

  • Sphaerichthys osphromenoides (Osphronemidae)
  • Betta foerschi (Osphronemidae)
  • Parosphromenus bintan (Osphronemidae)
  • Pangio semicincta (Cobitidae)
  • Sundadanio axelrodi (Sundadanionidae)

The waterparameters are in optimal range with help of the peat and leaves. The water is shallow and dark, pH is low and the flow rate is slow. The fern leaves above the water shade. All of these thing increase the fishes comfort.

The aquarium decorations visually break up the place for the fish peace so none male Betta foerschi disturbs the other territory. I feed the fishes some frozen food (bloodworm, brine schrimp) and I breed or collect live food for them (blackworm, mosquito larve, daphnia, enchytraeus).

Plant care

The aquatic plants found in aquarium

  • Cryptocoryne ciliata (Araceae)
  • Lemna minor (Araceae)
  • Salvinia cucullata (Salviniaceae)

These plants haven’t any special needs. The light is enough for the plants growing. I planted Cryptocoryne in a box with sand 6-7 cm and garden soil substrate 1-2cm. I don’t use any fertilizer.

Water care

I chang 50% water every two week with rainwater that I prefilter with active coal and cottonwool. I check the filter media every week and, if neccesery, I clean it. I treated the sand in Cryptocoryne with hydrochloric acid so that the calcium is in it doesn’t influence the pH value and hardness.


95 cm
40 cm
35 cm
133 L

Substrate in aquarium

Stone form
Submerged terrestrial vegetation


  • Biodiversity research and conservation in Borneo’s peat-swamp forests by Mark Harrison, Susan Cheyne, David A. Ehlers Smith
  • → A new tetraploid variety of Cryptocoryne ciliata ( Araceae ) from Sarawak by Niels Jacobsen, Karen Rysbjerg Jensen, Jan D. Bastmeijer, Marian Orgaard
  • Unique Southeast Asian peat swamp forest habitats have relatively few distinctive plant species by W. Giesen , L.S. Wijedasa and S.E. Page

Comment by the expert

Heok Hee Ng: I took points off for: (1) not using fish species that are strictly geographically correct (Betta foerschi and Parosphromenus bintan are not known from Sarawak), and (2) using too many floating plants (peat swamps typically do not have much floating plants, largely consisting of Utricularia if it is present).

Greg Martin: A superb recreation and a beautiful entry.