Glass eels, with a weight of up to 1 gram per head, can be successfully raised in a pond or aquarium that maintains a dissolved oxygen level of 5 ppm. To ensure successful
rearing, it is important to address the main cause of glass eel mortality, which is generally related to water salinity and the method of capture before rearing. Glass eels require a salinity range of about 5-6 ppm, which can be achieved by add a quarter tablespoon of salt to every liter of freshwater.
A rearing period of 55-60 days is necessary to promote growth to elver size. During the sorting process for elver size, the pond’s salinity level should be reduced to a quarter teaspoon per liter of water.
Additionally, it is important to consider the water’s acidity (pH). Glass eels and elvers prefer a pH close to neutral, around 7. If the pH is too high, ketapang leaves can be used to lower it. The eels’ survival rate is also influenced by their feed. For glass eels, artemia is recommended as a food source, which can be hatched by soaking the mother’s artemia for 24 hours. Artemia that are healthy and hatched float.
To feed a population of 1 kg glass eel every day, 6-7 tablespoons of natural food are used. Artemia is fed for 4-5 days before switching to bloodworms or silkworms for one week. Afterward, pellets that are adjusted to their mouth size are used to feed the eels until they reach elver size (4-5 grams/head).
