[TheOldSalt]

# SPS - Small polyped stony corals which require high intensity lighting.

# Salinity - The amount of salt in the water. Measured by Specific Gravity or Refraction.

# Saltwater Bath or Dip - A therapeutic technique for helping to remove some kinds of parasites from many freshwater fish. Salt is added to conditioned water and the fish is placed in the solution for a period of time to rid it of external parasites and stimulate slime coat production.

# School - A group of one kind of fish oriented together in a synchronized fashion, with uniform distance between individual fishes, traveling at the same speed and/or oriented in the same direction and position.

# Scientific Nomenclature - A standardized system used to name fish (and all other living creatures) which assigns a unique two-part name in which the first word indicates the genus and the second the species, e.g., Corydoras paleatus, the peppered Cory catfish. This is a valuable help, even to the hobby Fish-keeper, since common fish names can vary greatly from country to country, and even within the same country.

# Seasonal Fish - See Killifish.

# Shimmy - A stress-related symptom in which a fish remains in one position while wagging it’s body from side to side. Common among Livebearers, especially Mollies, when water conditions are not within the parameters for the fish’s needs.

# Shoal - A group of fish loosely gathered together but with variable distance between individuals and moving in various directions and/or oriented in various positions. Fish that shoal together will often school when on the move or in response to a threat.

# Siphon - An arrangement whereby water is induced to flow naturally from an upper level to a lower level through a pipe or hose which spans an intermediate level that is higher than either.

# Slime Coat - The continuously produced mucous envelope which covers the scales of a fish and makes it feel ‘slippery.’ Its purpose is to act as a barrier against disease-causing organisms, to act as a buffer in the internal/external gas exchange systems of the fish, and to save energy by reducing friction with the water when swimming. When a fish is subjected to Stress the Slime Coat becomes thinner.

# Soft Water - Water with a low content of dissolved minerals and solids. Usually Acidic.

# Sparring - Aggressive encounters between two fish (usually males) involving Display, Lip-Locking, or other forms of contest.

# Spawn - 1. v. To deposit and fertilize eggs. 2. n. The fertilized eggs of fish. The offspring of fish.

# Spawning Mop - Acrylic yarn tied together to provide a place for fish to Spawn.

# Species Tank - Also Species Aquarium. One in which fish of only one species are kept. Compare with Community Tank.

# Specific Gravity - A measure of density in comparison to pure water at a specific temperature. In this context, it is used as a measure of Salinity.

# Spirulina - A type of Blue-green Algae often fed to both saltwater and freshwater fish. Contains pigments that enhance blues and greens in fish.

# Sponge Filter - A simple Internal Filter in which water is drawn through a synthetic sponge which traps particles and provides a surface on which nitrifying bacteria can grow.

# Stress - A condition in which the organism is subjected to unfavorable or unfamiliar environmental conditions, resulting in some alteration in normal physical functioning. Short-term stress can often be overcome. Long-term stress can reduce resistance to disease and parasites, inhibit self-healing processes, and reduce life-span.

# Substrate - 1. The material spread out on the bottom of the aquarium, such as gravel, sand, or layers of different materials. Used as a planting medium or for decoration and attachment site for Biofilm. 2. Any surface on which living organisms are attached.

# Sump - A water reservoir below a tank (usually a marine aquarium) through which water is circulated by means of gravity and a pump. The sump can be used to house filters, heaters, and other equipment to keep them out of sight. In addition, it increases the total water volume of the aquarium system and thus helps to stabilize it. Some maintenance tasks can be performed in the sump, reducing the need to disturb the main tank and its inhabitants.

# Swim Bladder -An internal air sac which can contain more or less air according to the needs of the fish at the time. More air helps the fish become more buoyant, while less air allows the fish to swim down to deeper levels. Also called Air bladder. Serves to keep fish properly oriented in the water. Also creates and amplifies sounds.

# Swim bladder Disease - A condition in which the Swim Bladder fails to function normally. Causes vary. Symptoms include an inability to maintain normal upright position, or difficulty swimming down to lower levels of the water column.

# Target fish - Fish added to an aquarium with aggressive breeding fish. These fish serve as a ‘common enemy’ upon which the breeding pair can vent their aggression, preventing the pair from attacking each other. Compare Dither Fish.

# Theme - A looser equivalent of the Biotope Aquarium, it gathers fishes and/or plants coming from different biotopes but from the same general region, e.g., "Amazon Theme" or "South-Asian Theme".

# Trace Elements - Chemical elements which are required, usually in tiny quantities, for healthy growth of fish, plants, and invertebrates. These elements are normally supplied by regular water changes or in salt mixes for marine aquariums, but in certain cases it may be necessary to supplement this.

# Trickle Filter - A type of Bio-filter in which water to be purified trickles over the media held in a tray or chamber not submerged in water. This increases the amount of oxygen available to the bacteria, promoting Nitrification.

# Turnover - Or Turnover rate. The rate at which the total volume of the tank water is processed through the Filter system. Three or four times per hour is usually the minimum for a freshwater tank. Certain aquarium situations often require many times this basic turnover. See GPH.

# UGF - Under Gravel Filter. Perforated plates rest on the aquarium bottom and support the gravel substrate. Using lift tubes and power heads, water is pulled down through the gravel, up into the tube, and returned to the water column. Not usually recommended.

# UGJ - Under Gravel Jets. A DIY system of pipes and outlets set up to circulate water just above the Substrate, to reduce Dead Spots or the accumulation of Mulm on the Substrate. A pump or power head forces water through a network pipes which are buried under the gravel. Water is forced through outlets placed at various positions above the Substrate, keeping the particles in suspension until taken up by the Filter.

# VHO - Very High Output Fluorescent lighting.

# Velvet Disease - Fish disease caused by the protozoan parasite (Piscinoodinium). Also called Gold Dust. The main symptom of infection is dusty or velvety patches on the skin ranging in color from grey to a rusty yellowish-red.

# Vent - 1. n. The uro-genital opening of fish, located between the anus and the anal fin. Also referred to as the genital papilla. 2. v. To determine a fish's gender by examining the genital papillae.

# Ventral Fins - Pelvic Fins. The most posterior (toward the rear of the fish) set of paired fins on the underside of the fish.

# Venturi - A simple device for introducing a gas, e.g. air or CO2, into a water stream in a pipe.

# WPG - Watts Per Gallon. The wattage put out by the aquarium lights per gallon of water in the tank. For example, a 10 with two 15 watt normal output Fluorescent lights will give you 3 watts per gallon.

# Water Change - To remove some of the water from an aquarium and replace it with fresh water. See article.

# Water Column - The water in the aquarium from the top of the substrate to the surface of the water.

# Water Conditioner - A chemical product formulated to treat tap water to make it safe for aquarium use. Water conditioners usually eliminate Chlorine and Chloramines but may also contain ingredients that bind heavy metals, detoxify nitrogen compounds, fortify the Slime Coat of fish, and have other beneficial effects.

# Water Parameters - The readings for measurable factors of water in an aquarium. Basic aquarium water parameters include Ammonium, Nitrite, Nitrate, pH, General Hardness, and Buffering Capacity. See article.

# Wet/dry Filter - A type of Bio-filter in which water flows across a special Substrate on which Nitrifying bacteria (as Biofilm) are attached. The Substrate is not submerged, but kept moist and moving in and out of the water, by the action of the water. Promotes Nitrification by increasing the availability of oxygen to the Nitrifying bacteria.