Tanks & filtrationTanks & stands · Filters · Nano tanks
Heat, light & flowHeaters · Lighting · Pumps & flow · Chillers
Water & testingTest kits · Water prep
Reef systemsProtein skimmers · Dosing & automation
Aquascaping & carePlanted tanks · Maintenance · Hardscape & tools
Breeding & quarantineQuarantine · Breeding · Transport & backup
  1. Home
  2. Glossary
Glossary

Aquarium Equipment terms, explained

Short, plain definitions of the words you'll see on product pages and spec sheets. Each one links to a guide when there's more to know.

A

Aqua soil
Nutrient-rich substrate for planted aquariums. Read the guide →

D

dKH
Degrees of carbonate hardness, a unit for alkalinity. Read the guide →
Drop checker
A small indicator that shows CO2 levels in planted tanks. Read the guide →

F

Fishless cycling
Establishing beneficial bacteria with an ammonia source before adding fish. Read the guide →

H

HOB
Hang-on-back filter that hangs on the tank rim. Read the guide →

N

Nitrogen cycle
The bacterial process that turns ammonia into nitrite and nitrate. Read the guide →

P

PAR
Photosynthetically active radiation, the light plants and corals use. Read the guide →
Photoperiod
How many hours a day the aquarium light is on. Read the guide →
Protein skimmer
A reef device that removes organic waste using fine bubbles. Read the guide →

R

RO water
Reverse osmosis water, purified for saltwater mixing. Read the guide →

S

Sump
A separate tank below the display that holds equipment and water. Read the guide →

T

Temperature controller
A device that cuts heater power if water gets too warm. Read the guide →
Turnover
How many times per hour a filter moves the tank's volume. Read the guide →