R - Aquarium Dictionary

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

Aquarium Fish Definition and Glossary

Ramshorn Snails :
is a smaller snail that is useful to aquarium hobbyists because they eat algae, leave plants alone, reproduce easily in the home aquarium and can be used a food source for certain fish species like puffers. More below:
Ramshorn Snails

abbreviation for Red Cherry Shrimp.

Reef Tank :
is a type of saltwater aquarium that is used to keep saltwater corals and other invertebrates. The reef tank often requires much higher lighting and more pristine water conditions that a fish-only or fowlr aquarium. Live rock and live sand is used as a food source for many of the invertebrates in these systems and as the primary biolical filter. Temperature, Salinity (specific gravity), pH, Calcium and alkalinity are some of the constantly monitored parameters in reef tanks since the organisms can be more difficult to keep than fish. Since reef tanks use much more intense lighting than standard fish only or fowlr tanks, nitrates and phosphates need to be kept at extremely low levels to prevent algae from growing all over the aquarium. Reef tanks are the ultimate setup for many hobbyists, but they can be very expensive and challenging to setup and maintain. RESEARCH is your best friend if you're interested in how to set up a reef tank.

Refractometer :
there are several different types of refractometers on Amazon, but for our purposes it is a device or piece of aquarium equipment used to measure the salinity of water. You place a drop or two of aquarium water on a prism and then while pointed at a light source, you view through the eye piece on the other end of the refractometer (opposite the prism) a reading of the salinity level. As the light passes through the water and prism it is bent or refracted. These refractometers are considered more accurate than the less expensive hydrometer because they can be recalibrated easily using pure water such as Reverse Osmosis or Distilled water. See:
Refractometer on Amazon

Reef Tank Safe
if a fish or invertebrate is labeled "reef tank safe" it means that the fish or invertebrate will not harm the corals in the reef tank. There are many fish species that will eat or nip at corals thereby inhibiting growth rates or killing the coral.

Refugium :
is usually a separate tank that is inline or connected to the main aquarium, but it doesn't have to be connected. A refugium is used to grow and harvest organisms (plants and animals) for feeding the animals in the display tank. The refugium is separated from the main tank because these organisms would not be able to grow their populations because of predation in the main aquarium. These animals are protected in a place of "refuge", hence the term refugia or refugium. By being inline or connected to the main tank, the refugium can be a place where you can grow beneficial macro algae that can aid in nutrient export from the system. You could also use the refugium as a place to grow macro algae and periodically cultivate it for feeding to your Tangs or Surgeonfish. Essentially, refugiums can be anything that you want them to be.

Repashy :
a brand of fish foods that gets decent reviews. They make specialty foods for the various fish species and amphibians. More here:
Repashy on Amazon

Replenish :
an aquarium supplement made by Seachem that is designed to replace minerals and general hardness (GH) in reverse osmosis water before adding it to the aquarium. See:
Seachem Replenish on Amazon

Respiration :
is the process fish use to extract oxygen from the water in order to live.

Reverse Osmosis :
is a water filtration process where water is pushed through a semi-permeable membrane. This membrane only allows certain types of atoms to pass through the membrane and stops the "bad" atoms from passing through. Reverse osmosis water can sometimes be 90% more pure than regular tap water. Sometimes an RO unit is used in conjunction with a Deionization filter. Also see:
reverse osmosis filter
Reverse Osmosis Unit on Amazon

Ricordea Florida :
see Ricordea Florida

RO :
abbreviation for Reverse Osmosis. See: Reverse Osmosis and Deionization for more information. Also see:
reverse osmosis filter
Reverse Osmosis Unit on Amazon

Root Tabs :
this is a gravel bed or sand bed supplement used for plant keepers. It provides essential trace elements, amino acids and vitamins for plants. See:
Root Tabs
Root Tabs on Amazon

Rock Scaping :
is the process of decorating or arranging the Live Rock in a saltwater aquarium. Also see Aquascaping

abbreviation for Red Tail Shark. See the profile and care information for the Red Tail Black Shark.

abbreviation for Red Tail Black Shark. See the profile and care information for the Red Tail Black Shark.