How It Works - Pool Controls Chemigem D10 User Manual

How it works:

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The ChemiGem D10 continuously analyses pool water chemistry while your pool system
is running. Valve models use the suction created by the main pool pump to feed accurate
doses of liquid chlorine and acid into the pool via solenoid valves.
The ChemiGem D10 can also be installed with dosing pumps (instead of valves) to feed
the chlorine and acid into the pool. Dosing pump models can be useful in certain
applications, such as where pool equipment is installed below the water level of the pool.
Note: the filter system should always be running when the pool is being used.
Oxidation Reduction Potential
The Chemigem D10 is measures how much chlorine is in pool water by measuring the
ORP of the water.
ORP stands for Oxidation Reduction Potential. Chemicals like chlorine destroy pathogens
(eg harmful bacteria) in water by oxidising them.
The level of oxidation available in the water can be measured chemically with an ORP
sensor contained in the ChemiGem's multielectrode (probe). This produces a voltage
related to the ORP of the water, which is a measure of the effectiveness of chlorine in the
water.
Varying the ORP will affect how long it takes to destroy harmful bacteria in pool water. For
example, if ORP is maintained at 650mV, E-coli type bacteria will be destroyed in around
one second. However, if the ORP is lowered to 550mV, the same organisms may take up
to 2 hours to be eliminated.
pH Control
When chlorine is added to water the pH always changes – this is because chlorine is not a
neutral chemical. The pH will slowly rise as chlorine is added to the water. A rise in pH
greatly reduces the effectiveness of the chlorine as a sanitiser, so it is important to ensure
that the pH remains in the correct range.
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The pH of the water can be lowered by the addition of acid – and your ChemiGem
does
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this automatically. The ChemiGem multielectrode (probe) measures the pH of the water
and doses the pool with small amounts of acid to keep the pH in the correct range.
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