T - Aquarium Dictionary

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

Aquarium Fish Definition and Glossary

Tannins :
usually comes from leaves that turn the aquarium water into a more suitable environment for certain fish species. Tannins are leached from driftwood, leaves and peat moss and they lower the pH naturally but make the water slighlty yellow or brown in color. Check out catappa leaves for more info:
Catappa Leaves
Catappa Leaves on Amazon

T5 HO :
a newer type of High Output fluorescent light that is 5/8 inch in diameter and is more effecient than standard T12 fluorescent lights. These lights require a special ballast and are slimmer in size, allowing you to put more light over the tank. Typical life spans for a T5 bulb is reported to be in the 18 - 24 month range. HO T5 lights are gaining in popularity with Saltwater reef tank and freshwater planted tank hobbyists because they can grow some of the more light demanding species without adding too much heat. T5 hoods have fans that pull heat out the sides of the hood. For fixtures, see:
T5 Fixture
T5 Fixtures on Amazon

is an abbreviation for Total Dissolved Solids. You can measure the amount of total dissolved solids using a TDS meter. Reef tank keepers use a TDS meter to track how well their reverse osmosis or RO/DI filter is running and the measured level of total dissolved solids using a TDS meter can indicate when it is time to replace these RO or RO/DI filters.
TDS Meter
TDS Meter on Amazon

Tang :
The Tang or Surgeonfish is common name for a saltwater fish species. They are also known as surgeonfish because of the scalpel like growths at the base of the caudal peduncle which they use for aggression and defense.

Target Feeding :
is a feeding process for filter feeders (corals) where you use a turkey baster (or something similar) to deliver the food directly to the animal. Slowly push the bulb on the baster to allow the food to cloud over the filter feeder.

Taxonomy :
is the scientific practice of classifying of naming animals by species. The most famous taxonomist was Carl Linneaus.

Temperature :
for fish tank purposes, temperature refers to how hot or cold the tank water is. We measure temperature in degrees Fahrenheit (°F) or degrees Celsius (°C). While keeping fish and invertebrates it's important to have slow temperature variances. Temperature swings in either direction that are too drastic can be quite stressful for fish. An aquarium heater and aquarium chiller are used to keep the tank water within a certain range.

Test Kit :
for running an aquarium it is very important to have a test kit that allows you to test your water parameters for the ammonia, nitrite and nitrate levels at a minimum. If you are dealing with algae issues you may also want to invest in a phosphate test kit. There are master test kits that contain all of these tests in one kit which allows you to save a little bit of money over buying the test kits individually.
Test Kit
Master Test Kit on Amazon

Test Strips :
used to test aquarium water for pH, ammonia, nitrites and nitrates. Test strips are thought to be not as accurate as the liquid test kits and the results are more difficult to interpret than liquid tests. However, due to their convenience and cost they are quite popular with hobbyists and better than not testing at all.
Test Strips
Test Strips on Amazon

The Bag :
a filter bag made by Seachem that is supposedly more durable and lasts longer than conventional filter bags. See:
The Bag
The Bag on Amazon

Thrive :
a planted tank additive that is used as a plant fertilizer made by NiloCG Aquatics. It is an all in one fertilizer and contains micro and macro nutrients plants need.
Thrive on Amazon

Thermometer :
a device used to measure the temperature of the aquarium. The old fashioned mercury style thermometers are still available as well as the new fancy digital type thermometers that helps take the guess work out of getting the temperature reading.

Timer :
refers to an electrical device that incorporates an internal clock to turn the devices on that are plugged into it. We highly recommend a timer for your aquarium lights. You can achieve some cool effects with a multi-timer device. For instance, if you have a light hood with full spectrum bulbs and actinic bulbs you could have the actinics come on at 10 am and stay on until 10 pm to achieve a sunrise and sunset effect. The full spectrum bulbs could come on at 12 pm and stay on until 8 pm.
Automatic Timer on Amazon

Top Fin :
an aquarium product manufacturer (Petsmart brand?) known for making aquariums, filters, heaters and replacement cartridges. See:
Top Fin on Amazon

Trace Elements :
is used in reference to saltwater for our purposes. Trace elements in natural saltwater are those elements that are present in less quantities than the major elements that make up saltwater. These elements may be less in quantity or (PPM) but can be just as important. Examples of trace elements in NSW (natural salt water) that are supplemented in saltwater aquariums include Iodine, Molybdenum and sometimes Iron.

stands for Tetra Safe Start, which an aquarium water additive for establishing beneficial bacteria in a new aquarium.
Tetra SafeStart on Amazon

Triggerfish :
a type of saltwater fish. See Triggerfish page for a list of fish profiles.

Trickle Filter :
an aquarium filter that incorporates a type of wet-dry filtration. Aquarium water is dripped (trickled) over plastic bio-balls (various types of media available) that are partially exposed to air. This type of filtration enhances the biological filtration in the filter. See:
trickle filter
Trickle Filter on Amazon

Tubercles :
refers to the small white dots or pimple like growths around the gill covers of male goldfish. Can be used as an indicator in determining the gender differences in Goldfish and Koi.

Tubifex Worm :
a fish food, tubifex is a worm that is fed as an occassional treat to fish that is high in protein and other nutrients. Breeders will sometime use this in conjunction with other high quality foods to prepare their fish pairs for breeding. Live tubifex worms will quickly spoil if not kept in clean conditions and if that happens dispose of them, don't put spoiled worms in your tank. They also come in freeze-dried form, although they may not be as nutritious as the live version, they are much easier to keep and administer in freeze-dried form.
Tubifex Worms on Amazon

Turkey Baster :
yes, we put the word "turkey baster" in the aquarium dictionary (Ha!). Actually though, this is an invaluable tool that serves many purposes with aquarium keeping. You can use it to: target feed corals, siphon up detritus and uneaten fish foods, collect baby fish, squirt off detritus from rock work and plants, glaze a turkey, squirt your kids if they get too close to the tank, etc. Get one, really!
Turkey Baster
Turkey Baster on Amazon

Turn Over :
refers to the amount of water flow through a filter or the total amount of water movement within the tank. For example, if your filter is rated at 300 GPH and you have a 55 gallon aquarium, your turn over rate is 5.5. This simply means that you "turn over" the tank water 5.5 times per hour.