Why the bottom of the tank shapes this job
Corydoras spend their day with their faces in the substrate, sifting for food with whisker-like barbels that are easily irritated by grit and decaying debris. That single fact changes how you clean their glass: everything you scrape loose eventually sinks, and it lands exactly where the corys eat. So the goal is not merely clear panes but a controlled cleanup, done immediately before a partial water change, with downward strokes that carry the loosened film into the water column your siphon is about to remove rather than dusting it across their feeding ground.
Stroke downward, rinse the pad often
Start with clean, soap-free hands and a plain aquarium pad, and work from the waterline down in overlapping passes, rinsing the pad in a bucket of tank water each time it loads up. Near the substrate, slow right down: a pad that dips into sand or gravel picks up grains, and one careless upward sweep after that can scratch glass and rain grit over the bottom. Corydoras often startle as a group when a hand first enters, darting in a brief, comic flurry; hold still for a few seconds, let the shoal regroup, and they will usually resume sifting within arm's reach of your hand.
Leave a little grazing where it does no harm
Not every pane needs to be spotless. The front glass deserves a full wipe for viewing, but a light film left standing on a back or side pane is harmless and gives algae-grazing tankmates something to work on between meals. What matters for corydoras is the state of the bottom afterwards, so finish by checking that no grey-green sludge has settled in the corners they patrol. If a visible dusting remains, pass the siphon lightly over those patches during the water change that follows rather than stirring the whole substrate up with more scrubbing.
Watch barbels as your cleaning report card
Healthy corydoras carry long, intact barbels and sift confidently; barbels worn short often trace back to dirty substrate conditions rather than to the glass itself, which is why post-cleaning fallout matters so much for this species. After a cleaning session, watch the shoal feed: eager sifting and relaxed grouping mean the disturbance stayed where it belonged. If several corys go off their food, hover listlessly, or show reddened, shortened barbels, test the water, increase gentle bottom siphoning, and consult an aquatic veterinarian if the signs persist beyond a couple of days.
Make the paired routine easy to hand over
Glass cleaning in a cory tank is really a two-part job, wipe then siphon, and it falls apart when one person wipes on Saturday and another assumes the siphon happened too. Writing it as a single duty with both halves named removes the guesswork for anyone covering the tank while you travel. KinsLe's Care Teams supports exactly that handoff: the combined cory-tank duty can be assigned to a named helper and marked complete with a timestamp only when both the panes and the follow-up siphon are finished.