G - Aquarium Dictionary

Updated August 12, 2019
Author: Mike - FishLore Admin
Social Media: FishLore on Social Media

Aquarium Fish Definition and Glossary

abbreviation for Granular Activated Carbon.

Gammarus :
a freshwater amphipod that is used to feed fish.

Gang valve :
a valve that is used with multiple air lines to direct and regulate air flow to each of the tubes.

Garlic :
garlic is primarily used in trying to get finicky fish to start eating. The garlic juice entices them and some hobbyists claim it works well. Some fish foods are starting to come with garlic as one of the ingredients because of the increased feeding response. You can soak the fish food in garlic prior to feeding them. See:
Garlic Guard
Garlic Guard on Amazon

stands for German Blue Ram or the Great Barrier Reef in Australia.

General Cure :
is an aquarium medication made by API that is used to eliminate parasitic fish diseases like gill and skin flukes, hole-in-the-head, swollen abdomen and wasting disease. It can be used in both freshwater and saltwater aquariums. More info:
General Cure
General Cure on Amazon

GH :
abbreviation for General Hardness. This is a measurement for the total amount of dissolve minerals in your tank. Use a test kit to measure:
GH Test Kit on Amazon

Genital Papilla :
is the tube through which the sperm and eggs pass on fish and can only usually be seen during breeding. Angelfish has a genital papilla.

Genus :
is a taxonomic group of similar organisms that has one or more species. For example, for the freshwater angelfish, Pterophyllum scalare, Pterophyllum is the genus and scalare is the species.

abbreviation for Ground Fault Circuit Interrupter. A GFCI outlet is a safety device that will prevent you from getting shocked or electrocuted. When the circuit detects a difference in electrical flow through the outlet it will trip the circuit, preventing serious damage to the aquarist from happening. These are a must have around aquariums. It's also a good idea to always turn off the electricity to the tank before working in it. GFCI's look like this:
GFCI Outlet
GFCI Outlet on Amazon

Goldfish :
is a type of freshwater fish. Also see the Goldfish profile page.

abbreviation for Gallons Per Dat. This term is often used when referring to how many gallons of water a reverse osmosis filter or RO/DI filter can produce in a day.

abbreviation for Gallons Per Hour. This term is used when referring to filter turnover or water turn over within an aquarium.

Gills :
are used by fish to extract gases (oxygen) from the water. Also see: Respiration.

Gonopodium :
is a modified anal fin for reproductive purposes. Also see: Livebearer Fish.

Gorgonian :
is an octocoral species that can take on various forms such as branchlike, encrusting or whiplike. Some species contain zooxanthellae, while other gorgonian species do not.

Gourami :
is a type of freshwater fish. Also see the Gourami fish species profiles page.

Gravel :
is used as an aquarium substrate on the bottom of the tank. There are tons of different gravel options from un-natural colored rocks, to fake polished gems to more natural looking river gravel:
Aquarium Gravel
Aquarium Gravel on Amazon

Gravid Spot :
is a term usually encountered when dealing with the freshwater livebearing fish. Gravid simply means carrying and developing eggs. The gravid spot is usually a dark spot located near the anal vent and is often easily seen in fishes such as the guppy and swordtails. In Mollies and platies it may be more difficult to see, especially in darker colored fish.

Green Killing Machine :
an economical UV Sterilizer for aquariums that is also one of the most popular sterilizers amongst hobbyists. Used to eliminate cloudiness, algae and bacteria in aquarium water. See:
Green Killing Machine on Amazon

Green Water :
the result of an algae bloom, green water can be unattractive to look at but shouldn't harm the fish. The amount of dissolved nutrients in the tank are the primary cause of green water. For ideas on how to correct green cloudy water, please read cloudy aquarium water.

Grindal Worm :
sometimes called dwarf white worms, these are white worms that reach about 1/2 an inch in size and they are used to feed smaller fish species and fry.

reference to Green Star Polyps or Green Spotted Puffer