Why the spray bottle stays under the sink
The outside of an aquarium pane collects two kinds of grime: greasy fingerprints from hands that steady the glass during feeding, and white crusts where drips from water changes dried in place. Both look like a job for glass cleaner, but an aerosol or trigger spray is the worst tool near an open tank. Every squeeze sends a fine mist into the air, and some of that mist settles on the water surface or drifts onto the rim, where the next drip washes it in. The fish never see the cloth touch their water, yet the chemicals arrive anyway. Warm water dissolves exactly the deposits you are fighting — dried tank water is mostly mineral residue, and skin oils lift readily — so the cleaner adds risk without adding cleaning power.
Two cloths, warm water, nothing else
Set up a pair of microfiber cloths that belong to the aquarium alone, ideally a colour nobody uses elsewhere in the house. One cloth does the washing: dampen it under the tap with warm water and wring it until it feels barely moist, because a dripping cloth runs water down the stand and into seams. The second cloth stays completely dry and does the polishing, its fine fibres picking up the last moisture before it can dry into streaks. If a mark resists — a stubborn drip line under the rim, say — dampen the cloth a touch more and hold it against the spot for a few seconds to soften the deposit, then rub gently. Never apply anything directly to the glass itself: liquid goes on the cloth, cloth goes on the glass, and nothing ever gets sprayed.
Polishing pane by pane
Start with the front pane at eye level, where smears show most, working from the top down so any loosened grit falls away from the area you have already finished. Use small overlapping circles with light pressure; pressing hard on a dry patch can drag a trapped grain of sand across the glass and scratch it, which is why the damp pass comes first. Move to the side panes, then crouch and check the front again from a low angle — raking light reveals streaks that look invisible head-on. Wipe the rim and the top edge last, since drips from the lid gather there, and finish by drying the stand under the tank so no moisture sits against the wood or the silicone seams.
Keeping the finish between wipe-downs
Most of the haze you polish off arrives through habits, not accidents: hands on the glass to lean in for a closer look, wet fingers straight from a water change, a lid lifted and set down dripping. Drying your hands before touching the tank and lifting the lid slowly so water runs back inside cuts the marks dramatically. Launder the two cloths on their own, with no fabric softener — softener coats the fibres and smears grease instead of lifting it — and store them in the tank cabinet so they never migrate to a kitchen drawer. When the routine lives on KinsLe as a Care Teams task with the last wipe marked done, whoever feeds the fish that day can see at a glance whether the glass is due, and ten unhurried seconds with the dry cloth keeps it that way.