Ideal Tank Conditions
Breeding can be very successful in even a small tank at a temperature of anywhere from 72F to 80F, with 75F being ideal. These fish prefer normal not too hard, slightly acidic water—the kind of water that is natural in the Florida Everglades, around which the farms where these fish come from are located.
One interesting breeding method is to use a bare tank, which should be thoroughly cleaned and contain soft brown peaty water. In the bare tank, place two or three nylon mops that have been sterilized by boiling. Note: especially if you have used these mops in other breeding projects, they must be free of any biological residue.
The easier way to breed the more forgiving Glowlight Tetra is to used well-aged, natural chlorine-free water—for example, rainwater from a rural area. Or you can use reverse-osmosis water that has been left standing in the thoroughly clean tank along with 3-4 bunches of fine-leafed plants for about a week at a temperature of anywhere from 68F to 79F. Fully aerate the water for 4-6 hours before introducing the breeders, which should be conditioned separately for 7-10 days on live and frozen foods.
One final note on water condition: Using ½ existing aquarium water from the pair's home tank, add ½ well-aged fresh water with 3 bunches of fine-leaved plants also works, just as well as long as you are using a commercially-bred pair of Glowlight Tetras. In reality, the pair are probably breeding in your community aquarium already, if you keep your fish well-fed and the water in good condition, but the eggs will be eaten as soon as they are laid and you will never see them.
The Glowlight Tetra should be bred in a dim room—neither the breeding process itself nor the fry should be exposed to sunlight or bright light of any kind.
A large pair should be selected and conditioned until the female is literally bulging with roe (eggs). They should be placed into the breeding tank carefully in the late afternoon. The next day, after some love play, which takes the form of short darts at each other, the male and female come side-by-side and lock fins. Then, trembling in close contact, they roll over, in or against the plants or nylon mops.
The fine-leaved plants or nylon mops are important, as they allow the fish to brace themselves for the fertilization process. However, the type of plants is not as important as placement—place the plant clumps well apart from each other to allow the fish to swim among them as the eggs are laid and fertilized.
As the breeding pair roll over and touch fins, up to 300 eggs are laid in batches of about 8-16 at a time. The eggs are only slightly adhesive, so don’t worry if many of the eggs fall to the bottom, as they should not mildew and the parents are not as quick to eat the eggs as other Characin species. The eggs that fall to the bottom will still be fertile; however, overall fertility may be low because of the way in which these fish mate.
Caring for Eggs and Fry
Naturally, remove the parents as soon as possible after noticing they have finished breeding activities. The Glowlight Tetra is not the avid egg eater that many other Characin species prove to be, so don’t panic, but do get them out when breeding activities have stopped.
The fry hatch in about 24 hours and then hang on plants and the glass sides of the tank for another day or so. They become free-swimming on the third day and should be fed infusoria and egg yolk the first 5-7 days, followed by commercial powered growth food and baby brine shrimp. After two weeks, the young are easy to raise and grow quickly! At about 3-4 months, if you have followed an aggressive and varied feeding program, you may be ready to introduce your own school of brightly colored Glowlight Tetras into your aquarium.