For harlequin rasboras, think in terms of the school, not the fish. One harlequin eats almost nothing, but a school of eight or ten feeding together will clear a small pinch of micro pellets or well-crushed flake in around two minutes, and that two-minute pinch, twice a day, is the right meal. Scatter it across a wide area of surface rather than dropping it in one spot, because a school feeds as a shifting group and a tight food patch lets the boldest fish circle it while the rest hang back.
The mouth sets the menu size
A harlequin's mouth is small and angled upward, built for picking insects and tiny items from the surface film and upper water. Standard flake pieces and ordinary pellets are simply too large — the fish mouths them, spits them, and the food ends up in the substrate while the rasbora stays hungry. Micro pellets, or flake crushed between finger and thumb to fragments, convert the same pinch into food every fish can take. If you watch closely and see repeated taking-and-spitting, the size is wrong before the amount is.
Feeding a school is a distribution problem
Rasboras are peaceful, mid-water schoolers that feed in loose formation, and their shyer members eat last. The amount that works is the amount at which the whole school is still picking items at the ninety-second mark and the last pieces go before two minutes — if the front fish are full and drifting while food still sinks, the pinch was right for the group but dropped too tightly. A gentle current from the filter outflow helps spread a pinch naturally. In a mixed community tank, feed the rasboras their scattered pinch while bolder tankmates are occupied with their own food at the other end.
What a well-fed harlequin looks like
The copper body should carry a gentle fullness behind the black wedge after feeding, settling back to slim between meals. School-wide thinness, with the wedge looking pinched and colors washed out, means the group ration needs to grow slightly — increase by a fraction of a pinch rather than adding a third meal. Frozen micro foods such as baby brine shrimp or daphnia, rotated in as part of the same two-minute amount, suit their insect-eating nature and bring out the color that tells you the diet is right.
Where the extra food ends up
Because each portion is small, rasbora overfeeding is slow and subtle: a gradual haze of waste in the plants, snails multiplying on the surplus, water changes creeping closer together. The school will also graze biofilm and micro-life between meals, so a missed feed is genuinely harmless. If several fish stop schooling up to feed, or you see white stringy waste trailing from multiple fish, check water quality and reduce portions, and consult an aquatic vet if the school stays off its food.
A scattered school pinch is easy for a second person to repeat an hour later without realizing, so logging the pinch and its time in KinsLe's Care Teams keeps your rasboras fed by the group amount, once, as planned.