Harlequin rasboras are forgiving fish in a stable tank, and the one thing that reliably goes wrong while their owner is away is kindness measured in pinches. These coppery schoolers are small, their food is small, and the difference between a correct meal and a water-quality problem is about ten seconds of extra shaking from the tub. Your brief should remove every judgment call: pre-measured food, a named feeding moment, and a short list of what the school should look like when things are fine.
Measure the meal with your own hand first
Harlequins feed in the middle of the water column and pick at fine particles, so demonstrate the ration in person if you can: the amount of crushed flake or micro-pellet the school clears completely in about two minutes, with nothing drifting down to rot on the substrate. Then divide that amount into one labeled container per day of your trip. Tell the feeder plainly that the wedge-marked fish will crowd the surface looking hungry at every visit, because schooling fish always beg, and that an empty container is the full instruction. A second helping is the single most likely cause of cloudy water and stressed rasboras by the time you return.
Explain what a settled harlequin school looks like
Your feeder needs a picture of normal before they can spot abnormal. A settled group of harlequin rasboras holds loosely together in open water, copper flanks and dark wedges vivid, drifting and darting as one when food arrives. Fish parked separately in a corner, hanging at the surface, or showing washed-out color across several visits deserve a message to you. So does a school that stops coming up to feed, because rasboras in good water are eager at the surface layer where their food lands. Keep the language observational: you are asking for descriptions, not diagnoses, and a short phone photo helps you judge from wherever you are.
Cover the lid, the light, and the filter in one breath
Harlequins are not notorious jumpers, but any startled schooler can clear a gap, so ask the feeder to slide the cover glass fully closed after every feed. The light should already be on a timer; the feeder's job is only to confirm it came on, since a dark tank all week usually means a tripped timer rather than sick fish. Filter flow for this species should stay gentle, and the feeder should simply check that water is moving and the unit is not rattling or silent. If the filter has stopped, the instruction is to call you, not to open it and experiment.
Set the water rules in plain terms
For a trip of a week or so, a stable harlequin tank needs no water change from a visitor, and attempting one with the wrong water is riskier than leaving well alone. Leave a topped-up jug of treated water for evaporation losses only, marked clearly as top-up water, and store your conditioners and bottles out of the feeding area so nothing extra gets added on a hunch. If the water turns visibly cloudy, the feeder should skip the next feed and contact you; fasting a day harms rasboras far less than another meal dissolving into already struggling water.
Write it down as one page the feeder can follow
Keep the finished brief to a single page in feeding order: container of the day, watch the school eat, lid closed, filter moving, lights on timer. Note your phone number, your aquatic shop's number, and the one circumstance that always earns a call, which is several fish behaving oddly at once. That same page can sit inside KinsLe's Care Pass, giving your holiday feeder temporary access to the rasboras' routine and tank details only while you are away, so nothing depends on a scrap of paper staying on the fridge.