The glowlight tetra (Hemigrammus erythrozonus) is a small fish known only from the Rio Essequibo in Guyana where it is found primarily in forested areas, in tributaries off the main river channel. The water here is typically stained a dark brown with tannins from decaying organic material and is often highly acidic. This fish grows to an adult size of 1.6 inches long. Mature females are noticeably more round and often a little larger than the males.
All glowlight tetras entering the aquarium trade are mass bred on commercial farms in various parts of the world. Because of this, it is a very adaptable fish. Extensive captive breeding has also led to wide availability of an albino form.
Glowlight tetras should be maintained in an aquarium of 10 gallons or larger. A soft, sandy substrate (CS7538) is a good choice. Driftwood (ZM2000) and live or artificial plants may also be incorporated.
Glowlight tetras prefer a temperature of 75°F to 82°F, a pH of 5.5 to 7.5, and a hardness of 2 to 15°H. Be sure water is clean and well oxygenated.
The glowlight tetra is a very peaceful fish well suited to a planted aquarium. Good tank mates include other tetras, livebearers, danios, rasboras, cory catfish, loricariid catfish, gouramis, and dwarf cichlids. Keep them in groups of 6 or more.
Glowlight tetras are easy to feed fish accepting almost any appropriately sized food offered. In the aquarium they will readily accept flakes (AL165) and small frozen foods. For maximum color, growth, and health these fish will look their best when given probiotics (AL169) in addition to a balanced diet.