Indian glassy fish

1) Where they come from

Indian glassy fish (Parambassis ranga) come from slow-moving waters across India, Bangladesh, and nearby areas—think weedy edges, canals, flooded fields, and calm river backwaters. They’re built for cruising in open water, weaving through plants, and picking off tiny critters.

2) Setting up their tank

These fish look delicate, but they’re not made of glass—what they hate is unstable tanks and being kept in tiny groups. Give them a settled aquarium and a bit of space to school, and they relax fast.

• Tank size: I’d start at 20 gallons long for a group; 30+ gallons is even nicer if you want a proper school
• Group size: 8–12 is where you start seeing the real behavior (less hiding, less fin-nipping)
• Filtration: moderate flow is fine; they like clean water but not a washing machine
• Temp: mid-70s°F works well (around 24–26°C)
• Decor: plants (real or fake), driftwood, and open swimming lanes down the front
• Lighting: they look amazing under soft-to-medium light with a darker background

I’ve had the best luck with a planted tank that has “rooms”: dense plants on the sides/back and open water in the middle. They’ll hang midwater and flash that silvery see-through look when they feel safe.

3) What to feed them

They’re micropredators. In plain English: they love small meaty foods, and some individuals act like flakes are suspicious at first. Once they learn, they eat like little piranhas (without the teeth).

• Staples: quality micro pellets, small flakes, and finely crushed community pellets
• Frozen: brine shrimp, daphnia, cyclops, bloodworms (more like a treat than daily)
• Live (if you do it): baby brine, daphnia—great for conditioning and getting shy fish eating

If you’ve got a new group that’s being picky, try frozen daphnia or brine first, then mix in pellets. Once one fish “gets it,” the rest usually copy.

4) Behavior and tankmates

In a good-sized group, they school loosely and hover midwater, facing into the current. In small groups, they get twitchy—more chasing, more pecking, and more time hiding behind the heater like they’ve seen ghosts.

• Good tankmates: peaceful tetras, rasboras, danios (not the super hyper ones), peaceful barbs, Corydoras, small loaches, peaceful gouramis
• Be careful with: long-finned slow fish (they may nip), super pushy feeders that outcompete them
• Avoid: big cichlids, fin-rippers, anything that can fit them in its mouth

Males can spar a bit, especially if you have just a few fish. In a bigger school with plants breaking up lines of sight, the drama drops way down.

5) Breeding tips

They’re egg scatterers and will absolutely eat their own eggs if given the chance, so breeding is one of those “separate setup” situations. It’s doable though, and pretty fun if you like raising tiny fry.

• Condition the adults with frozen/live foods for a week or two
• Use a breeding tank with a sponge filter and lots of fine plants (Java moss, spawning mops, fine-leaf stems)
• After you see spawning (chasing + quick taps into plants), pull the adults out
• Feed fry infusoria/microworms first, then baby brine shrimp once they’re big enough

6) Common problems to watch for

Most issues I’ve seen come down to stress from small groups, newly set up tanks, or getting outcompeted at feeding time. Once they settle, they’re pretty steady fish.

• Shyness/hiding: usually a too-small group or not enough cover—add more fish (if the tank allows) and more plants
• Fin nipping: often happens in cramped tanks or tiny groups; rearrange decor, add sight breaks, and bump the group size
• Refusing dry food: start with frozen/live and transition gradually
• Ich and other common parasites: they can show it after shipping stress; quarantine new fish if you can
• Poor color/looking “washed out”: bright bare tanks do this—add background, plants, and reduce harsh lighting