An organism that causes disease.
PETCOCK A small,
manually-operated faucet or valve for draining off liquids or releasing air
pressure. The air-relief valve on a filter is an example.
A term used to indicate the level of acidity or alkalinity of pool water. Too
low of pH causes etched plaster, metal corrosion and eye irritation. Too high of
pH causes scale formation, poor chlorine efficiency and eye irritation. The
ideal range for pH in swimming pools is 7.4 to 7.6.
A chemical reagent dye used to test for pH. It can measure pH from 6.8 to 8.4.
PLASTER A mixture of white
cement and white marble dust used as an interior finish, which can be tinted,
colored or left white; applied to the gunite or shotcrete of a pool or spa.
A substance made of giant molecules formed by the union of simpler molecules.
Many water clarifiers are made from organic polymers. An example would be
polymerized ethylene, called polyethylene.
related) The active ingredient and
chemical name of a non- chlorine shock treatment or non-chlorine oxidizer. Does
not kill bacteria or algae but it will oxidize or destroy ammonia, nitrogen and
swimmer waste. It has a low pH, and it does not increase chlorine or bromine
levels the way that super chlorination does, so water may be entered in 15
minutes after addition. It will also reactivate bromine to its killing form,
An abbreviation for parts per million. It is a weight-to-weight expression. It
means 1 part in 1 million parts, such as 1 lb. of chlorine in 1 million lbs. of
water. Many of the common pool water tests, as well as acceptable ranges, are
stated as ppm. For example, free available chlorine should be kept between 1.0
and 3.0 ppm; total alkalinity should be between 80 and 120 ppm; and and water
hardness should be between 200 and 400 ppm.
A substance separating, in solid particles, from a liquid as a result of a
chemical or physical change. It also means to form a precipitate.
diatomaceous earth (D.E.) onto the filter grids or elements.
PRESSURE GAUGE A gauge
with an analog dial indicating the pounds per square inch (psi) of pressure that
has built up within a closed container, such as a filter.
psi An abbreviation for
pounds per square inch.
PUMP A mechanical device,
usually powered by an electric motor, which causes hydraulic flow and pressure
for the purpose of filtration, heating and circulation of pool and spa water.
Typically, a centrifugal pump is used for pools, spas and hot tubs.
PUMP CAPACITY The volume
of liquid a pump is capable of moving during a specified period of time. This is
usually gallons per minute (gpm).
PUMP CURVE Also called a
pump performance curve - A graph that represents a pump's water flow capacity at
any given resistance.
PUMP STRAINER BASK. Pump
Strainer Basket - A device placed on the suction side of the pump, which
contains a removable strainer basket designed to trap debris in the water flow
without causing much flow restriction. Sometimes called a "hair-and-lint trap."