Choose dimensions around behaviour
Footprint matters for territorial cichlids and active livebearers; height matters for angelfish; surface area matters for bubble nesters. Do not use gallons alone to choose a tank.
Keep equipment predictable
Use a reliable heater where needed, a thermometer, a mature sponge filter or protected intake, a secure cover and enough light to observe fish without stressing them.
Add only useful structure
- Fine plants or mops for egg scatterers.
- Floating cover for bubble nesters.
- Broad leaves or slate for angelfish.
- Caves for plecos and cave-spawning cichlids.
- Visual barriers and exits for pairs that may become aggressive.
Make cleaning safe
Arrange the tank so uneaten food and waste can be removed without dismantling territories or trapping fry.
Prepare the grow-out destination
The breeding tank may be too small for juveniles after the first weeks. Mature the next filter before the move.