The process of flow reversal to clean a filter and to restore it to the normal clean condition for filtering with a minimum resistance to flow through the media.
BACKWASH CYCLE
The operating time, after the filter cycle, required to completely clean the filter.
BACKWASH PIPING
The pipe extended from the backwash outlet of the filters to a terminus at the point of disposal.
BACKWASH RATE
The rate of application of water through a filter during the cleaning cycle expressed in gallons per minute per square foot of effective area.
BACTERIA
Any of a class of microscopic plants having round, rod-like spiral or filamentous single cell or non-cellular bodies, often aggregated into colonies or mobile by means of flagella. Living in soil, water, organic matter or the bodies of plants and animals and being autotrophic (self-generative), saprophytic (digests chemicals already in their environment) or parasitic.
BACTERICIDE
Material capable of inhibiting or destroying bacteria. Function is known as bactericidal.
BACTERIOSTATIC
Material capable of reducing the rate of bacterial growth. Sometimes confused with bactericidal.
BATHER
Any person using a pool, spa or hot tub and adjoining deck area for the purpose of water sports, recreation or related activities.
BEGINNERS AREA
Those water areas in pools, spas and hot tubs which are three feet (3) or less in water depth.
BILL OF MATERIALS (BM)
List of parts that are assembled into a pump at the factory
BINDERS
When used in reference to cartridge filters, refers to chemicals used to hold, or bind, short fibers together in a filter. Also may refer to various chemicals used to bind polymeric compounds in products such as plastic bottles.
BIOFILM
An aggregation of active, multi-layered microbes found on surfaces and in particular inside tubing and pipes. May be difficult to remove by chemical means due to multiple layers and lack of fluid dynamics at surfaces where it resides.
BLINDING
The fouling or plugging of pores in a membrane, usually by a gel-like substance.
BOD
Biochemical oxygen demand.
BODY FEED
The continuous addition of small amounts of filter aid during the operation of a diatomaceous earth filter.
BOOSTER PUMP
A pump that adds pressure to existing pressure in a water system.
BOOSTER PUMP SYSTEM
A system whereby one or more hydrojets are activated by the use of a pump which is completely independent of the filtration and heating system of a spa. In other uses it is generally a pump and pressure tank controlled by a pressure switch or other device.
BRACKISH WATER
Water containing between 1000 and 15000 mg/l of dissolved solids is generally considered to be brackish.
BREAKTHROUGH
The first appearance in the effluent of an adsorbate of interest under specified conditions.
BRIDGING (OR SALT BRIDGING)
The caking of salts in a dry water softener tank which causes failure of the liquid or brine beneath the dry salt to become saturated. The net result of bridging is insufficient salt to properly regenerate the resin.
BRINE
(Same as Reject Water): One of two streams of fluids generated by a Distiller or Reverse Osmosis unit. It contains the impurities removed from the feed water. Characteristically, 30,000 to 300,000 ppm.
BROMIDE
A compound of bromine. Two of the salts, Sodium and Potassium Bromide, are sometimes used to produce a disinfectant or algaecide.
BROMINE
An element which is sometimes used in pool water purification. A dark, heavy, reddish-brown liquid in its normal state. Closely related to chlorine.