DIATOMACEOUS EARTH:

The filtering medium of the DE filter, this dry powder is the fossilized remains of the ancient diatoms, a hard shelled form of algae. Found as a sedimentary rock that is easily broken down into a fine powder.

 

DIATOMACEOUS EARTH FILTER:

A filter tank that features fabric covered grids which hold DE powder up against the flow of the water in order to filter out dirt and impurities as fine as 1 micron.

 

DICHLORO-S-TRIAZINETRIONE:

A chemical compound. It is an oxidizer used to make bacteriocide, algicide, and cleaning agents. Reacts with water to form hypochlorous acid, which is related to bleach.

 

DISINFECTANT:

Chemicals or processes which work to destroy vegetative forms of microorganisms and other contaminants. Examples are chlorine, bromine, Soft-Swim, and ionizers; also included are copper and silver algaecides.

 

DIVERTER VALVE:

Used in a twin port skimmer, a diverter allows the operator to manipulate the amount of flow from the main drain and skimmer to the pump.

 

DPD:

A method of testing for chlorine levels in the pool water. Unlike OTO, DPD testing allows determination of total and free available chlorine levels which through subtraction gives us combined levels.

 

DRAIN:

Also called the "main drain," this plumbing fitting is the start of one suction line to the pump and is usually situated at or near the center bottom of the pool.

 

DRY ACID:

Sodium bisulfate, a granular form of acid used to lower pH and alkalinity in the water. It is safer and less caustic than muriatic acid. Usually available as a "pH decreaser."