Breeding Neon Tetras
Much of the success in breeding tetras depends on the treatment the fish have received months before actual spawning. It is best to obtain eight or so youngsters from a reliable source and then rear them to maturity. When the females begin to fill up with eggs the sexes are separated for a week or two and given the best in the way of aquarium management and feeding. This process is called conditioning.
The Planted Tank Method
This is perhaps the oldest method of breeding tetras. A small or medium-sized tank of about five or ten gallons is furnished with fine-leaved plants, coarse gravel (1/8″ diameter) or pebbles (1/2″ diameter). Care is taken to see that no snails, planarians, or other egg or fry destroying creatures are introduced. When all is ready the conditioned pair are transferred to the breeding tank. This is usually done late in the evening. By the next morning, the fish will have settled and commence spawning. Fertilization of the eggs occurs in the water. These then adhere to plants or fall to the bottom. The end of the spawning session is heralded by the pair losing interest in each other and starting to browse around in the plant thickets or the aquarium floor, seeking eggs to devour. At this stage the parents are removed. The eggs hatch in a few days and the fry can be seen hanging on the plants and the glass wall of the tank. A few days later they become free-swimming. Tetra fry are very small and need infusoria as a first food.
Artificial Spawning Media
The main advantage of using an artificial spawning media such as willow root and nylon mops over fine-leaved green plants is that with this system one can have a clean, easily reproducible setup free from snails and planarians. The bottom of the tank is lined with an inch layer of boiled pebbles and then filled with suitable water (ie. peat water). A handful of cleaned and boiled willow root or some nylon mops are introduced and the tank is now ready to receive the conditioned fish.
Acriflavine Adsorption Method
Acriflavine and various other dyes are commonly employed when breeding tetras to prevent fungus growth on eggs. A tank is filled with suitable water (not treated with peat). Enough of a solution of acriflavine is added to produce a final concentration of about 1 milligram/gallon in the tank (this amount is not extremely critical). Let this stand for a day or two, then add boiled willow root. The dye will be absorbed by the root and the water will become crystal clear in a few hours. The breeding pair is now introduced. After spawning is complete the pair is removed and the tank is covered to exclude light. The fry hatch out in a few days. If willow root is not available, a charcoal filter could be used to remove the dye from the water. It is important to remove the dye prior to spawning, since acriflavine causing the eggs to be infertile.
Peat Water for Breeding Tetras
Tetras can be breed in water that had has been treated with peat, oak bark, or oak leaves. Peat water is prepared by adding handfuls of boiled peat to a quantity of rainwater. In time the peat sinks and the water becomes amber coloured; pH and hardness readings are taken and more peat added if necessary. Ideally the final water should have a hardness of about 2 ppm and a pH between 5-6.8.