Keeping the Setup Deliberately Simple
A fry tank succeeds by being easy to keep clean and easy to watch, so resist decorating it like a display aquarium. A small tank — large enough to dilute waste between changes but small enough that tiny fry can find food without crossing a desert — is the heart of the setup. A bare glass bottom shows you exactly where uneaten food and waste collect, lets fry graze fallen food instead of losing it in gravel, and wipes clean in seconds. If the bare floor reflects too much light for a shy species, a sheet of dark paper under the tank solves it without adding substrate.
Filtration and Warmth Without Hazards
Run an air-driven sponge filter. It filters biologically, barely moves the water, cannot trap a fry against an intake, and grows a film of microscopic food on its surface that fry graze all day. Seed it before the fry arrive by running it in the parents' tank for a couple of weeks, or squeeze a mature sponge into the new tank's water if time is short, because a brand-new filter in a brand-new tank has no bacteria to handle waste.
Add a small heater with a guard if the species is tropical, set to match the parents' tank, and confirm the temperature with a thermometer rather than trusting the dial. Position the heater where water movement passes it, and check it daily while fry are tiny, since small volumes swing temperature faster than large ones.
Water That Matches Home
Fill the rearing tank with water taken from the parents' aquarium during a water change, topped up with dechlorinated water of the same temperature. Matching the water the fry hatched or were born in avoids the shock of new chemistry at the most delicate moment of their lives. Keep a spare container of conditioned water ready so small daily changes take minutes rather than becoming a production that gets skipped.
Cover the tank with a lid or mesh. It slows evaporation, holds warmth, keeps household dust out, and stops a startled larger fry from jumping as the batch grows.
Light, Cover, and Feeding Stations
Give fry a normal day-length of moderate light on a timer. Add one generous clump of fine-leaved plants, moss, or a spawning mop, weighted or floating, where fry can shelter and graze. Beyond that clump, keep the floor open so you can watch every fish at feeding time and count the batch in seconds — a headcount is your earliest warning system in a fry tank.
Feed in the same open area each time. Fry learn the station quickly, gather where food reliably lands, and you can judge appetites and belly fullness far better than when food drifts into cover. A pipette or small spoon keeps portions controlled in a small volume.
The First Fortnight's Routine
For the first two weeks, your routine is feeding little and often, siphoning the floor daily with airline tubing, and topping up or changing a small amount of water most days. Test the water if fry stop feeding or gather at the surface, and act on the result with a water change before anything else. Keep equipment for this tank separate where you can, or rinse shared nets well, so nothing unwanted travels from other aquariums. In KinsLe, Care Teams lets you assign the morning feed, the evening siphon, and the water top-up to different family members, with each completed task timestamped so the fry tank's simple routine never silently slips.