A fish move fails on small omissions: bags that split, a pump with flat batteries, nothing to test the water with at the other end. Pack the kit as four systems — catching, containment, breathing and testing — assemble it a week before moving day, and every item on this list earns its space by solving a problem that genuinely happens in transit.
Catching: get them out without injury
A soft, fine-mesh net in a size that fits your tank, plus a smooth, rigid container — a clean jug or small tub — for guiding fish into underwater rather than lifting them thrashing in a net. Add a torch for the corners of a half-drained tank, and a siphon hose, because most fish are far easier to catch once the water is low and the decor is out. A second pair of hands belongs on this list too, if only as a planned phone call.
Containment: bags, bands and the box
Strong fish bags in two sizes — smaller bags for single fish, larger for groups and big individuals — bought in generous quantity, because spares are the difference between a mishap and a disaster. Double-bag everything: one bag inside another, the inner one's corners taped or inverted so fish cannot wedge into a point, the second sealed against leaks. Fill each bag about one-third water from the tank and two-thirds air, twist, and secure with elastic bands — keep a fat bundle of bands, they perish and snap. The box is an insulated, opaque cool box or a polystyrene shipping box: it holds bags upright, keeps them dark, which calms fish enormously, and evens out temperature swings in a car. Line it with newspaper or towels so bags cannot roll.
Breathing and temperature: the battery pump and thermometer
Bagged fish on a short hop across town need nothing more than the air sealed in the bag. For long journeys, staged moves or any holding time at the other end — fish waiting in bags or a holding tub while their tank is rebuilt — a battery air pump becomes the kit's most important item: pump, fresh batteries fitted, spare batteries, airline and an air stone. Test it running the week before, not on the morning. A simple aquarium thermometer tells you whether the box is drifting hot or cold in the car; heat packs or a frozen bottle, wrapped and never touching the bags directly, are the corrections, used only if the thermometer says so.
Testing and the small essentials
At the destination, the test kit decides whether fish go straight into reset water or wait: pack liquid tests for ammonia and pH at minimum, ideally nitrite too, and test both the holding water and the refilled tank before releasing anyone — a moved tank can cycle again briefly. Around these systems sit the small essentials: water conditioner for any fresh water used, towels you accept will be ruined, tape and a marker to label every bag with species and bagging time, spare conditioned water in a sealed bottle, and a written plan with the order of work at the new house. If a friend is housing some fish overnight mid-move, brief them properly rather than by text message: KinsLe's Care Pass gives that helper temporary access to your fish's care details — what they eat, what the water should read, who to call — for exactly the days they are responsible, and no longer.