The safe window for corydoras left at home
Corydoras catfish can be left with once-daily checks for the span of most short trips — several days without concern, and around a week in an established, sensibly stocked tank. They are hardy, social bottom dwellers, but their position in the tank shapes the risks: waste, uneaten food, and low oxygen settle at the bottom first, exactly where a corydoras spends its life.
The window narrows if the tank is newly set up, the group includes very young fish, or the substrate was already overdue a clean when you left. It widens in a mature tank with a clean floor and a filter in good order. Anything well beyond a week calls for more than a daily look-in — an experienced person able to test water and change some of it mid-trip.
The checker's first job is food that reaches the bottom
A corydoras can starve politely in a tank that is being fed. Surface and mid-water fish intercept flakes and floating food long before anything drifts down, so a checker who feeds 'the tank' the usual way may never feed the corydoras at all. Your holiday instructions need a separate, sinking portion for the bottom — a measured piece of wafer or a small set of sinking pellets, portioned by day before you leave.
Ask the checker to drop the sinking food where the group rests and to glance a few minutes later that the corydoras are nosing over it. Feeding toward the evening suits their natural rhythm, since corydoras grow more active as light fades. One portion a day is plenty on a trip; a missed day harms them far less than doubled portions rotting into the substrate.
Bottom conditions are what the daily glance protects
A daily corydoras check should read the bottom of the tank. The visitor confirms the filter is running, looks along the substrate for any fish that has died — a body on the floor fouls the corydoras' own layer fastest — and watches the group itself: healthy corydoras rest together, whiskers intact, and stir into activity when food lands.
Note the warning signs worth a call to you: several corydoras hanging at the surface gulping air far more than their occasional quick dart upward, fish sitting apart and listless, or cloudy water. Occasional air-gulping is normal corydoras behaviour and your notes should say so, or a conscientious checker will panic at a healthy habit. Top-offs, if needed, use only the conditioned water you prepared.
Prepare the floor before you prepare the feeder
Corydoras forgiveness on a trip is earned before departure. Vacuum the substrate thoroughly in the days before you go, because trapped waste releasing into the water column mid-trip is the bottom layer's main hazard. Check the filter's flow, confirm the group's barbels look whole and the fish are feeding eagerly, and settle the tank back to routine for at least a couple of days before leaving.
Write the visit as a short list, agree which findings earn a phone call, and leave a backup contact for anything mechanical. KinsLe's Care Teams hold the corydoras routine as a checklist for your helper, and the dated entries confirm the bottom feeders were fed and watched on every day of the trip.