HALOGEN:

A member of the family of elements fluorine, bromine, chlorine and iodine.

 

HARD WATER:

Water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap.

 

HAZMAT:

A hazardous material, a term used almost exclusively in the United States, is any solid, liquid, or gas that can harm people, other living organisms, property, or the environment. Hazmats may be radioactive, flammable, explosive, toxic, corrosive, biohazardous, an oxidizer, a pathogen, an allergen, or may have

other characteristics that render it hazardous in specific circumstances.

 

HEATER:

A device used to heat the water. It may be electric, fuel operated or solar powered heat.

 

HEAT EXCHANGER:

A set of 8 or 10 ribbed copper tubes that absorb the heat produced below it and transfer it to the water cycling through its tubes.

 

HEAT PUMP:

The antithesis of the air conditioner, the heat pump's cooling coil removes heat from the air while the condenser coil transfers it to water cycling through it.

 

HOT TUB:

Usually considered a circular, wooden vessel filled with heated and circulated water.

 

HP:

Horsepower (hp) is the name of several non-metric units of power. The most occurring conversion of horsepower to watt goes 1 horsepower = 745.7 watts.

 

HYDROXIDES:

the most common name for the diatomic anion OH−, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known.

 

HYPOCHLORITE:

A family of chlorine compounds such as Calcium Hypochlorite and Lithium Hypochlorite, both granular, and the liquid Sodium Hypochlorite. When these compounds contact water, they release Hypochlorous Acid, the active sanitizing agent.

 

HYDROSTATIC PRESSURE:

A force involving built up ground water which creates upward pressure beneath the pool shell.

 

HYDROSTATIC RELIEF VALVE:

Fitting(s) installed in the floor of the pool designed to manually or automatically release hydrostatic pressure beneath the pool by allowing ground water into the pool.