Photo: Daiju Azuma · CC BY-SA 4.0
Freshwater · Beginner · 10+ gal
Boraras brigittae
By Fishy Dave
Chili rasboras (Boraras brigittae) are ~0.6-0.8 inch red nano schoolers for a densely planted 10-20 gallon. Keep 10-12 or more with soft acidic water, gentle flow, dark substrate, and micro foods. A 10-gallon is a species-only floor; use 20 gallons if you mix in other fish.
| Water type | Freshwater |
|---|---|
| Care level | Beginner |
| Minimum tank | 10 gallons |
| Temperament | Peaceful nano schooler. Keep 10-12 or more so they school in the open instead of vanishing into plants. Plant-safe. Skip anything that outcompetes them at feeding or treats a half-inch fish as a snack. |
| Diet | Micropredator with a tiny mouth. Micro pellets, crushed flake, frozen baby brine, and microworms. Small portions once or twice daily so the back of the school gets a turn. |
| Temperature | 72–82 °F |
| pH | 4.5–6.5 |
| Hardness / salinity | Soft, acidic water is where color holds. Shop fish often tolerate near-neutral community water if it stays stable and clean, but alkaline, hard tap usually washes the red out. Harder to keep colored than ember tetras in typical US tap. |
Boraras brigittae is a Borneo cyprinid sold as the chili rasbora or mosquito rasbora. Adults stay about 0.6-0.8 inch. Males show a deeper red with a dark lateral stripe when they are comfortable in soft water and a real school; females stay rounder and a bit paler. This page is about chili rasboras, not harlequin rasboras, not phoenix or lambchop rasboras, and not ember tetras with the orange dialed up.
They use the middle of a densely planted tank. Moss, fine stems, leaf litter, and a dark substrate bring the red out. A bright bare tank leaves them washed out and glued to cover. A lid helps but is less critical than for jumpy danios; still useful if the tank sits near traffic or kids.
A school of 10-12 or more in a densely planted 10-gallon is an honest species-only home if filtration and weekly water changes stay on schedule. Move to a 20-gallon when you add shrimp, embers, or other midwater fish so the group still has room. Length beats height; they cruise through the plants in short hops. See stocking a 10-gallon tank for layouts that leave midwater room.
Soft, acidic water is the real difference from ember tetras. Embers usually hold orange in near-neutral community tanks. Chilies often fade to dull pink in alkaline, hard tap even when they eat well and the tank is clean. If your tap is hard, plan on RO mixed with remineralized water, or expect muted color. The GH/KH/pH guide covers how to read those numbers without turning the tank into a chemistry project.
Gentle flow matters. A hang-on-back with the outflow baffled, or a seeded sponge filter, is enough. Soften anything that blasts the midwater. Set the heater in the 72-82 F band, which works for most shop fish. Finish the cycle before you buy the school. Quarantine when you can.
Feed micro pellets or crushed flake they finish in a minute, then add frozen baby brine or microworms a few times a week. Leftover food in a planted nano is how nitrate climbs. Chili mouths are smaller than neon mouths, so flake that looks fine for a guppy can sit uneaten.
Tank mates that work: ember tetras, celestial pearl danios, adult cherry shrimp, and otos in a mature tank. Skip zebra danios and other fast, greedy midwater fish that clean the surface before the chilies get a shot. A low-tech planted layout with dark substrate fits them well. See the low-tech planted aquarium guide.
A few listings we would open for this species. Skip anything you already own that still works.
Hikari Tropical Micro Pellets, 0.77 oz
Chilies have tinier mouths than embers and a whole school to feed. These semi-floating micro pellets were made for small-mouthed tropicals; they sink slowly enough that the back of the group gets a shot.
A pinch once or twice a day, not a pile. Crush a few if the smallest fish still struggle. Frozen baby brine or microworms a few times a week still helps.
See this listingAqueon Adjustable Pro heater, 50W
A tropical 10-gallon species school wants stable mid-70s to low-80s F. Fifty watts is the size we open for most 10s in a normal room.
Step up to 100W if the tank is a true 20-gallon or the room runs cold. Put a separate thermometer on the glass away from the heater.
See this listinghygger sponge filter, small
A planted nano school wants gentle biofiltration without a current that pins half-inch fish to the glass. An air-driven sponge sized for a 5-10 gallon is a calm default.
Air pump and tubing are sold separately. Squeeze the sponge in old tank water only. A baffled hang-on-back is fine if you already own one and can dial the flow down.
See this listingA school of 10-12 or more is a solid start. Fewer fish in a tiny group stay shy and show less color.
A densely planted 10-gallon works as a species-only floor for 10+. Use a 20-gallon if you want a mixed community around them.
Soft, acidic water holds the red better than alkaline hard tap. Embers usually keep color in near-neutral community water; chilies often fade when GH and KH run high even if the tank is otherwise fine. Check GH, KH, and pH, then adjust with RO mix if needed.
No. Embers (Hyphessobrycon amandae) are South American characins, a bit larger, and more forgiving of hard tap. Chilies are Boraras cyprinids from Borneo blackwater, tinier, and more plant- and soft-water dependent for color.
Next step
Plan on 10 gallons or more. Put your actual tank size into the stocking calculator and it shows what else can live alongside them.
Open the stocking calculatorBefore you buy
Keep your fishies swimming.
Freshwater · Beginner
Hyphessobrycon amandae
Ember tetras (Hyphessobrycon amandae) are ~0.7-1 inch orange nano schoolers for a planted 10-20 gallon. Keep 10 or more with gentle flow, plants, and micro foods. A 10-gallon works for a species school; use 20 gallons if you mix in other fish.
Min. tank: 10 gal
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Danio margaritatus
Celestial pearl danios (Danio margaritatus), also sold as galaxy rasboras, are ~1-inch nano schoolers for a planted 20-gallon. Keep 10-15 with gentle flow, dense plants, and dark substrate. A 10-12 gallon long is a tight species-only floor, not a comfortable community home.
Min. tank: 20 gal
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Neocaridina davidi
Cherry shrimp (Neocaridina davidi) are beginner invertebrates if the tank is cycled and copper-free. A starter colony of 10+ needs about 5 gallons; 10 gallons is easier. They need minerals for molting, not a second fish-page clone.
Min. tank: 5 gal
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