Licorice Gourami Care Guide: Parosphromenus in Blackwater
Few freshwater fish are as visually arresting and as demanding as the licorice gourami. Males of most Parosphromenus species display extraordinary iridescent colouration — blues, greens, and reds that shift with every angle — but only under very specific water conditions. A complete licorice gourami care guide must begin honestly: these are specialist fish for experienced hobbyists willing to invest in an ultra-soft, blackwater setup. At Gensou Aquascaping at 5 Everton Park, Singapore, they’re among the most rewarding species we work with.
Species Diversity Within Parosphromenus
The genus Parosphromenus contains over 30 described species, most from peat swamps and blackwater streams of Peninsular Malaysia, Borneo, and Sumatra. Common species in the trade include P. deissneri, P. ornaticauda, P. harveyi, and P. nagyi. All share the licorice gourami form — compressed, elongated body with lyre-shaped tail — but colour patterns vary enough that species identification requires care. Many wild localities are critically threatened by habitat destruction, so responsible sourcing from reputable breeders matters.
Water Parameters: Non-Negotiable
This is where most failures occur. Parosphromenus are obligate blackwater fish. They require extremely soft water (GH 0–3, ideally under 2), acidic pH of 4.0–6.5, tannin-stained water, and temperatures of 24–28°C. In Singapore, RO water is the only practical starting point — tap water at GH 2–4 is borderline and becomes more problematic as hardness fluctuates. A small RO unit (available locally for $150–300) produces water close enough to pure that you can then add tannins via Indian almond leaves, peat, or Borneo Wild Blackwater extract to reach the target pH.
Any deviation above GH 5 or pH 7.0 causes chronic stress, colour fading, and eventual immune collapse. These fish cannot adapt; they deteriorate. Test regularly and keep records.
Tank Setup: Recreating the Peat Swamp
A dedicated 20–40 litre tank for a pair or small group is ideal. Use dark fine sand substrate and cover it with dried leaf litter — Indian almond, dried oak, jackfruit, or ketapang leaves. Add Java fern, Christmas moss, or Bucephalandra attached to small pieces of driftwood. Keep lighting dim — a small, diffused LED on a timer providing 6–8 hours of low-intensity light. Heavy floating plant coverage (frogbit or salvinia) reduces light further and adds tannins.
Filtration should be minimal: a small sponge filter on the lowest setting, or even a small air-driven box filter with peat inside. Strong current stresses these fish significantly.
Feeding Licorice Gouramis
Parosphromenus are micro predators that rarely accept dry food reliably. Their diet should consist primarily of live and frozen micro foods: baby brine shrimp, micro worm, Grindal worm, and Daphnia. Many individuals can be trained onto frozen cyclops or frozen baby brine shrimp over time. Feed small amounts twice daily — these are small fish (3–4 cm) with correspondingly small stomachs. Overfeeding in a low-flow blackwater tank fouls the water rapidly.
Breeding: Cave Spawners With Complex Behaviour
Males establish caves — small ceramic pipes, bamboo tubes, or hollowed driftwood work well — and display intensely to attract females. The pair spawns inside the cave in a typical labyrinth fish embrace, depositing 20–80 small eggs on the cave ceiling. The male guards the eggs and incubates them, sometimes clamping the cave entrance with his body. Eggs hatch in 36–48 hours; fry are free-swimming within three days.
First foods must be tiny: infusoria or commercial fry food (Sera Micron) for the first five to seven days, then baby brine shrimp. Fry are fragile but grow steadily in stable blackwater conditions. Breed consistently only when water parameters are dialled in — failed spawning attempts in poor conditions are demoralising and damaging to the fish.
Conservation Note and Local Availability
Several Parosphromenus species are considered vulnerable or endangered due to peat swamp drainage across Southeast Asia. When sourcing these fish, prioritise captive-bred specimens from dedicated hobbyist breeders. Singapore has a small but committed community of Parosphromenus keepers — Gensou Aquascaping can connect you with reputable local breeders and help you source fish that haven’t contributed to wild collection pressure. Keeping and breeding licorice gouramis responsibly is a meaningful contribution to their conservation.
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