T-W

Tee - A plumbing fitting in the shape of a "T" used to connect pipes.

Telepole - A long-handled aluminum pole, which extends in length. Various pool-cleaning tools, such as brushes or vacuums, may then be attached.

Test Kit - An apparatus or device used to monitor specific chemical residuals, levels, constituents or demands in pool or spa water. Kits usually contain reagents, vials, titrants, color comparators and other materials needed to perform tests. The most common pool and spa water tests are: pH, total alkalinity, free available chlorine, water hardness, cyanuric acid, iron and copper.

Test Strips - Small plastic strips with pads attached that have been impregnated with reagents that can be used to test pool water for residuals, levels, constituents or demands. The strips are usually dipped in the water, and the resulting colors of the pads are compared to a standard set of colors to determine concentration.

Time Clock - A mechanical or electrical device that automatically controls the periods that a pump, filter, heater, blower, automatic pool cleaner or other electrical devices are on or off.

Total Alkalinity - The total amount of alkaline materials pre- sent in the water. Also called the buffering capacity of the water. It is the water's resistance to change in pH. Low total alkalinity causes metal corrosion, plaster etching and eye irritation. High total alkalinity causes scale formation, poor chlorine efficiency and eye irritation.

Total Chlorine - The total amount of chlorine in the water. It includes both free available and combined chlorine.

Total Dissolved Solids - Also called TDS - A measure of the total amount of dissolved material in the water. It is comprised of the spent or carrier chemicals added every time chemicals are added, as well as the hardness, alkalinity, chlorides, chlorides, sodium, magnesium, calcium, etc. Maximum amount in pools is 2500 ppm. Maximum in spas is 1500 over starting TDS. The only way to effectively lower TDS is to drain part or all of the water and replace it.

Trichlor - A slow-dissolving, tableted or granular, stabilized organic chlorine compound providing 90% available chlorine. Used for regular chlorination but must be dispensed using a floating feeder or an in-line feeder (chlorinator). Trichlor contains an ingredient (cyanuric acid or stabilizer) that prevents the chlorine from being destroyed by the ultraviolet (UV) rays of the sun. Trichlor has a pH of 2.8, and regular trichlor tabs should not be placed in the skimmer as the low pH will corrode the metal components in the equipment.

Turbidity - The cloudy condition of the water due to the presence of extremely fine particles in suspension that cannot be trapped by the filter because they are too small. Adding a clarifier, such as an organic polymer or alum, will coagulate the particles and make the filter more efficient.

Turnover - Also called turnover rate - The period of time (usually in hours) required to circulate a volume of water equal to the volume of water contained in the pool or spa. Pool capacity in gallons, divided by pump flow rate in gallons per minute (gpm), divided by 60 minutes in 1 hours, will give hours for 1 turnover.

U

Underdrain - Also call filter laterals or lower collection system - Slotted, finger-like tubes that are attached to a sand filter manifold. The slots are on the bottom side to prevent the sand from passing through. Water comes into the filter tank, through the sand, into the underdrain, and then back to the pool.

Underwater Light - A fixture designed to illuminate a pool or spa from beneath the water's surface.

V

Vacuum - This term can be used to define any number of devices that use suction to collect dirt from the bottom and sides of a pool or spa. Most common is a vacuum head with wheels that attaches to a telepole and is connected to the suction line usually via the opening in the skimmer. It must be moved about by a person, and debris is collected in the filter.

Venturi - A fitting or device that consists of a tube constricted in the middle and flared on both ends. A fluid's velocity will increase and a fluid's pressure will decrease while pass- ing through the constriction. Placing a tube or pipe at the constriction point creates a vacuum. Fluid or air can then be drawn in through the tube. A hydro-therapy jet draws air in and mixes it with the water using this principle.

Vinyl Liner - The vinyl membrane that acts as the container to hold or contain pool water.

W

Water Clarifier - Also called coagulant or flocculant - A chemical compound used to gather (coagulate or agglomerate) or to precipitate suspended particles so they may be removed by vacuuming or filtration. There are two types; in- organic salts of aluminum (alum) and other metals or water-soluble organic polyelectro-lytes.

Weir - Also called skimmer weir - Part of a skimmer that adjust automatically to small changes in water level to assure a continuous flow of water to the skimmer. The small floating "door" on the side of the skimmer that faces the water over which water flows on its way to the skimmer. The weir also prevents debris from floating back into the pool after the pump shuts off.

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