A grazer's day is already half a meal
A hillstream loach does not wait for feeding time the way most fish do. Its flattened body and sucker mouth are built for holding onto smooth rocks in strong current and rasping away the film of algae and microscopic life that coats them, and a healthy loach works those surfaces for much of the day. That grazing is real food, which is why the prepared portion it needs is small: a piece of algae wafer roughly the size of its head, or a thin slice of softened zucchini or spinach, offered daily in a tidy tank and every other day in a mature one where algae visibly coats the stones and back glass.
Why a spotless tank changes the answer
The risk with this species runs opposite to most aquarium feeding. A newly set up or aggressively scrubbed tank may look beautiful and still hold almost nothing a hillstream loach can eat, because the biofilm it rasps takes time to establish on rock and wood. In that setting the daily supplement stops being a treat and becomes the whole diet, so feed every day without fail and leave some algae on at least a few rocks and one pane of glass on purpose. Strong flow matters here too, since it delivers the oxygen this loach expects and encourages the thin, tough algae growth it prefers over soft, stringy growth.
Offering the supplement so the loach actually gets it
Place the wafer or vegetable right against a favourite rock rather than broadcasting food into the current, where faster tankmates and the flow itself carry it away before a bottom-hugging loach reaches it. Many keepers drop the piece in shortly before lights-out, when the loach grazes undisturbed and shy tankmates compete less. Soften zucchini or spinach briefly in hot water so it sinks and yields to a rasping mouth, and weight it with a plant clip if it drifts. Remove what remains after a few hours, because a loach that has eaten its fill leaves the rest, and soft vegetable decays quickly in warm, fast-moving water.
Reading the belly and the behaviour
Check this fish from above and from the side each day. A well-fed hillstream loach has a smooth, gently rounded underside; a hollow dip behind the head, a pinched belly, or frantic rasping at bare glass for long stretches points to too little grazing or too little supplement. Competition is the other quiet cause: boisterous bottom feeders can claim every wafer while the loach clings nearby, so watch one full feeding to see who actually eats. A loach that suddenly stops grazing, sits in still corners away from the current, or breathes hard needs its water checked promptly, and an aquatic veterinarian consulted if the change persists after flow and oxygen are confirmed.
Keeping grazing checks from depending on memory
Rotate the small jobs this fish creates: one person checks the belly and the algae left on the rocks, another drops the wafer on scheduled evenings, and uneaten food gets lifted rather than left for the filter. Writing those turns down matters more than the portion itself, since the classic errors here are two people supplementing on the same day and nobody noticing a thinning fish for a week. KinsLe Care Teams lets a household assign those exact loach duties to named helpers and stamps each one done when it is finished, keeping the grazer's quiet routine visible to everyone.