The Glass Is Where Hillstream Loaches Live
A hillstream loach's flattened body and sucker mouth are built to hold it on glass and stone in fast current, and it spends most of its day exactly there, shaving algae and biofilm off the surface it clings to. That makes glass cleaning in a hillstream tank unlike any other: the surface you want to polish is the fish's floor, feeding ground, and refuge in one. The loaches are not stressed by your presence so much as by losing both their footing and their food in a single pass.
Scrub the Viewing Pane, Keep the Pasture Panes
Decide which panes are the loaches' and which are yours. The front glass can stay viewing-clear, but the back and one side pane should keep their film as standing pasture, along with smooth river stones left unscrubbed for grazing. When you clean the front, check the whole pane first: a well-camouflaged loach sits motionless and is easy to mistake for a smudge until the pad reaches it. Clean every section the pane offers except the square the loach occupies, and take that square on a later visit when the fish has moved off on its own.
Never Peel a Loach Off Its Spot
A hillstream loach that refuses to move ahead of your pad is telling you to stop, not inviting a nudge. Sliding a blade or pad under its sucker mouth can tear the delicate fin edge it seals with, and a loach knocked loose in high flow tumbles until it can catch a surface. Work up to a stationary loach and back away. These fish relocate constantly as they graze, so a patch skipped today is usually empty tomorrow — patience finishes the pane without a single forced move.
Keep Loosened Film Out of the Riverbed
In the strong current a hillstream setup needs, scraped algae does not drift down gently; it blasts around the tank and packs into the gravel and behind stones where the loaches graze and where flow cannot flush it. Clean immediately before a water change, keep the siphon running near the pane as you work if a second pair of hands is available, and wipe in downward strokes that deliver debris toward the intake. Rotting film trapped in the substrate undermines the clean, oxygen-rich conditions this species depends on.
Several Loaches Means Several Territories
Where more than one hillstream loach shares a tank, the glass divides into loose territories, and a loach chased off its square by a scraper may land in a neighbor's — the one way a peaceful cleaning creates a squabble. Read the pane as a map before starting: loach here, loach there, clean the gaps between them and leave each fish its own unwashed doorstep. In a group tank the front pane may never be fully clear on a single day, and that patchwork is the honest look of a tank cleaned around its residents.
Pasture Panes Stay on the Record
The agreement in a hillstream tank — front pane polished, grazing panes untouched, occupied squares always skipped — only works if everyone cleaning the tank knows which pane is which. Logging the grazing panes and the skip rule in KinsLe's Care Teams protects the loaches' pasture from a thorough helper who sees green glass and reaches for a blade.