- An abbreviation for outside diameter, used
when measuring tubing dimensions.
- Known as velvet disease, similar to ich but more
- A gas used in aquarium systems to break down organic
waste, raising redox levels.
- Pectoral fins
- Paired fins, one on each side of the body located
behind the gill covers.
- The stalk of a leaf.
- Measurement of the degree of water acidity. It is determined by the amount
of acids and bases in the water. If the amounts are equal it is called neutral
with a number rating of 7.0. If more acids it is called acidic with number
rating of less than 7.0, if more base it is called alkaline with a number
rating of more than 7.0.
- An element introduced into the aquarium through organic
or inorganic means that promotes excessive algae growth.
Can be removed through water changes.
- Physiological incompatibility
- The existence of some chemical or physical factor in the reproductive organs of a plant which prevents fertilization.
- A part of a leaf of a fern, corresponding to a leaflet in some flowering plants.
- Power head
- An electric pump that connects to the under gravel
filter tubes to greatly increase the water flow.
- Abbreviation for parts per million, a measurement used
in test kits.
- Quarantine tank
- A tank set up for newly acquired or sick fish to
isolate them from the main aquarium until they can be
- The continuation of the stripes in a fern that is divided.
- ORP or Redox potential is a measurement
of water purity and of a systems ability to break down
organic waste. The measurement is expressed in millivolts
by an ORP monitor.
- Synthetic media used for chemical filtration through a process known as ion-exchange.
- Reverse Osmosis
- A process of filtering tap water for use in the
aquarium. Water passes through a membrane which filters out
all elements leaving the water very pure. Trace elements
you want will have to be adjusted as well as the pH
- A stem growing more or less horizontally near the surface of the soil or gravel and sometimes showing above it.
- A very short, but often thick stem, growing vertically at or just above the surface of the gravel. Often referred to as the Crown.
- A horizontal stem growing just above the surface of the gravel and rooting at its nodes.
- The measurement of dissolved salts in the aquarium
- A term used to describe a leaf which has no Petiole.
- Soft water
- Water with a low concentration of dissolved salts.
- Specific Gravity
- The measurement used in marine systems to determine
- Species tank
- An aquarium where only one type of fish is kept.
- Used to describe the wavelengths of light produced by a
- Sponge filter
- a large foam rubber block connected to an air lift tube. Water is drawn through
the sponge, which acts as a mechanical filter and a bacteria colony. Especially
useful in breeding or fry tanks.
- The stalk of a fernleaf, corresponding to the petiole in flowering plants.
- A horizontal stem growing just below the gravel, as in many species of Cryptocoryne.
- Minute pores in the surface of leaves and Herbaceous stems through which
exchanges of gases with the atmosphere occurs.
- The material used to cover the bottom of the fish tank.
- Sulfuric salts in water. They form what is known as
- The body of a plant which is not differentiated into stem, root and leaf.
- Trace elements
- Minute substances found in water,that are needed for
proper plant and fish growth. Usually replenished with
partial water changes.
- Trickle filter
- A wet dry filter using a drip plate to disperse the
water over bio-media.
- Tritrate test method
- A specific method of water testing in which a reagent
is dropped into a sample until a color change is noticed.
More accurate than color comparison test methods.
- A modified bud, the leaves of which contain abundant storage reserves, by which the plant survives Winter and renews its growth in Spring.
- Turnover rate
- The number of times the water in an aquarium is passed
through the filtration system in one hour. The minimum
should be three or four times per hour
- Ultraviolet light, generally not wanted in the
aquarium. Special filters or shields are required for its'
- A unit designed to kill parasites and disease causing
bacteria with ultraviolet light.
- Under-gravel filter
- A type of filter placed under the substrate that
utilizes an air pump or power head to pull water through
the gravel and thus oxygenates the bacteria to help in the
nitrogen cycle. Not recommended for live plant tanks.
- The arrangement of veins in a leaf.
- Ventral fins
- Paired fins on the lower part of the fish, located
below the gill covers. Not all fish have these.
- A valve which makes bubbles by drawing air into fast flowing water. Especially
useful in protein skimmers.
- The manner in which a leaf, or the parts of a leaf, are rolled up in the bud. The same is true for the fronds of ferns.
- VHO lights
- Very High Output: florescent bulbs with a much higher
output than NO bulbs, they require special ballast and end
caps, mostly used on freshwater plant tanks or marine reef
- Any micro-nutrients needed for continued good health
of an organism. Many products are sold for specific
- Bearing young plants on vegetative organs, such as leaves.
- Water properties
- Elements used to determine water quality. Total
hardness, carbonate hardness, pH, ammonia, nitrate and
temperature are the most used indicators.
- Wave maker
- An electronic device that alternates power to different
powerheads to simulate wave motion.
- Wet-Dry filter
- A type of filter which has a portion of its media
exposed to the air with water flowing over or through it,
to greatly increase the oxygen content to the bacteria.
- A small worm used as food available either live or
- A group of more than two organs of the same kind, like leaves arising at the same level.
- The fear of aliens.
- Yeast method of
- A do-it-yourself method of supplying Co2 to fresh water aquariums. It involves
yeast, sugar and two liter bottles.
- Yellow water
- Name given to water with a slight yellow tinge. Can be
caused by too much organic material in the water or to show
that a water change is needed. Eliminated through carbon
filtration and better water management.
- Yolk sac
- A small container still connected to the baby fish after hatching, consisting
of the unabsorbed egg yolk.
- A substance used in fresh water aquaria for the removal
- Tiny animals or larvae of other animals living in water. usually used in reference
to marine aquaria.
- The symbiotic single celled brown or yellow algae
living in some marine invertebrates. They supply important
elements to their hosts.