Teach the School, Not the Single Fish
A harlequin rasbora is read as a group, so brief your sitter on the school's shape before you mention any individual. On a normal evening your harlequins hold together in the middle water, copper-orange bodies catching the light, each with a dark triangular wedge sweeping back from mid-flank. Show your sitter that formation and that colour, then describe its breakdown: the school loosening and never reforming, fish drifting to separate corners, wedges and copper fading to a washed pink-grey.
The Lid Rule for a Jumping Rasbora
A harlequin rasbora startles upward, so lid discipline belongs near the top of this briefing. Feeding, checking the thermometer, and topping up are all moments when a spooked fish can clear the surface and land on the rim or the floor, and a sitter who leaves the lid ajar while fetching food can lose a fish in seconds. The rule is simple enough to say out loud together: lid off only while hands are at the tank, lid seated fully before walking away. Ask them, if a fish is ever found out of the water and still moving, to return it gently to the tank with wet hands and tell you at once, rather than deciding on your behalf that nothing can be done.
Quiet Water Checks a Sitter Can Safely Make
A harlequin rasbora comes from slow, soft, plant-shaded water, and a school that goes pale is often reacting to a change in its water rather than to anything visible on one fish. Give your sitter three harmless checks: the filter is running and its flow is gentle rather than blasting the school into a corner, the thermometer reads where it usually reads, and no cleaning product, hand lotion, or aerosol has been used near the open tank. They should not adjust the heater, add conditioner beyond your written instruction, or perform a large water change to freshen things up, because rasboras handle a stable, imperfect tank better than a sudden swing toward perfect.
Feeding a School Without Fouling Its Water
Portion the harlequin school's food yourself, because small fish in a group invite a sitter to scatter extra for the ones at the back. Explain that every rasbora in a healthy school gets its share within moments, and the fish hanging back today is a fish to report, not a reason to double the ration and cloud the water for the other nine. Flake or micro food should land on a calm surface, so show them how you switch nothing off and change nothing about the filter just to feed; the routine they copy should be your routine, unchanged.
Pale Colour, Gasping, and the Call Threshold
Set the call threshold in the school's own language so your sitter does not have to interpret symptoms. Call you the same day if the wedges stay faded after the lights have been on a while, if several fish are breathing fast at the surface, if white spots appear across multiple bodies, or if any fish is found dead, since a death in a schooling fish asks a question about the shared water, not just that individual. The sitter removes a dead fish with a net, notes the time, and changes nothing else until you reply. They add no treatments and take no shop advice over yours; your aquatic contact is the backup call only if a fish is gasping and you are unreachable.
Write the Harlequin Briefing Around the Group
Recording the school size, its normal colour, and the fade-means-call rule in KinsLe as a Care Pass gives the person at your tank a reference they can check against the living school, instead of wondering whether pale rasboras are simply how your fish always look.