Heated Pools – Use of timers


Some basic considerations:

Tech “in basic terms…

  • The heat pump has a CE (coefficient specification). This means 1Kw of consumed power relates to 1 * x of output power. This is nowadays a nominal gain of 6. Therefore 1Kw = 6 Kw of heating power
  • This top spec occurs when the outside air temp is approx. 20 – 25 “c”.
  • When air temp (around heater) is less than the “CE” factor, then less heating power is achieved.

Set up & times of the year:

  • A heated pool is an ultimate indulgence of pleasure. Swimming in 29 “c” on a sunny day when the terrace is a warm 20 – 25 feels just fantastic.
  • Crucially it is the air temperature that attracts and detracts. Likewise, as we are considering the conditions in Spain we are pleased to note that such conditions occur from April till often the end of December.
  • As a rule of thumb heating the water by 10 “c” is efficient, this condition generally matches the “warm enough to take a dip” conditions from April to December.

The timers – when and when not to use.

  • The most efficient heating is achieved during warm air conditions (day time)
  • The most inefficient heating is during cold air conditions (night time)
  • Once a pool has reached that magic 29 “c” by raising water temperature by approx 10 “c” then maintaining that temp takes only a few hours a day (in best conditions – during the warm day light hours, 9am onwards)
  • Given the best time of day in terms of outside air temp is during the early afternoons, we can safely assume that most of us during these shoulder seasons will swim during the afternoons.
  • So, run the heating from 9am onwards – by setting the timer, and have warm water at the most economical cost for the afternoon swim. Generally, this will be only a few hours.

Heat Cover – inlet jets settings.

  • The cover must be active always. 
  • The inlets must be pointing downwards, pointing the incoming heated water towards the bottom of the pool not directly at the surface where heat loss is at its peak.
  • “Heatsavr” liquid pool cover, has achieved a net gain over a set point of 29 “c” to 30.5 “c” during warm day time sunlight in April, in my own pool.
  • “Heatsavr” liquid pool cover has likewise only lost 2 “c” with heater turned off between 11pm and 7.30am. (At 11pm outside air temp was 9”c”, at 8 am it was still only 5 ”c”)
  • The pool returned to 29 “c” by mid-day.
  • “Heatsavr” is added from the plant room at 7pm daily (1ml per m2).


This information is provided from my own pool. The specification being:
Dura 22 (22Kw heater)
Varispeed water pump running 2,000 rpm (approx. 650 watts) = + 2”c” inlet to output heating on 12,000 litres per hour.
Ultra Violet sanitation.
Dosatech chlorine feeder
Heatsavr liquid pool cover.
The heater is configured to auto run during the timer program whenever the water is less than the set point. 
Once heating to +10 “c” (March / April onwards), the timer function saves heating the water during the cold night air temperatures.
Using the timer assumes early morning swimmers will brave the cold 27 “c” potential conditions, however these “brave folk” will benefit from a warm swim during the afternoon.
Enjoy your pool, don’t just look at its beauty.


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Telephone / WhatsApp: 659 999 044.

The Ultra Violet Miracle..

Why it is crucial to have a good pool water disinfectant Policy.

The Objective is the creation of crystal clear water that is both comfortable to swim in, and 100% safe for humans from the undesirable effects of virus, bacteria and germs, as well as the unsighly appearance of algae formation. 

The problems, with negative effects on the water.

  • Human use, (cosmetics, sun creams, uric acid, urine).
  • Animal use and infestation (pets, birds insects).
  • Surrounding gardens (leaves, dust and dirt, even pesticides from neighbouring agricultural activity).
  • All creating the perfect breeding ground for virus, germs, bacteria and of course the ugly formation of algae. These micro-organisms need to be controlled by a planned considered program.

The Ultra Violet Solution.

The use of a chemical program has been for many years the traditional approach. Based upon chlorine disinfectant, this has worked, but has many bad side effects, made worse by the pool industries insistence to sell branded chemicals that cause over stabilisation, which in turn creates bleaching, itchy skin, red eyes, a carcinogenic environment and one that is unable to disinfect some of the most harmful bacteria and virus commonly found in swimming pools (Cryptosporidium parvum and Giardia lamblia).
  • ULTRA VIOLET as a part of the hygiene disinfectant policy…
  • Chlorine is an effective chemical method of removing most but not all health-related problems within the swimming pool. 
  • Ultra Violet is effect against all harmful health related problems.
  • Chemical solutions cause a change in state. Chlorine will oxidise and disinfect then changes state to become toxic. In its toxic state the chlorine becomes what is known as a chloramine. These chloramines cause itchy skin, red eye, give of ammonia gas etc. (see related article…http://www.yourpiscinacare.com/hygiene/chlorine-stabiliser)
  • When Chlorine oxidises and disinfects the water it will also affect the saturation index balance (see related article…).
  • Ultra Violet is a non-chemical disinfectant solution. It destroys the DNA of micro-organisms that badly affect the waters appearance and health qualities.
  • The water that passes through the Ultra Violet treatment before entering the pool is 100% perfect.
  • Once this perfect Ultra Violet treated water is in the pool, it then becomes infected by us humans and the surrounding environment. For this reason, a carefully calculated quantity of free active chlorine shall be added per day to ensure the water remains disinfected.
  • The Ultra Violet system enables the quantity of chemical used to be reduced to a minimal level without constantly damaging the saturation index.
  • The Ultra Violet system enables a reduced and controlled chlorine policy.
  • The Ultra Violet system reduces the fluctuations otherwise found in the saturation index.
  • The Ultra Violet system results in zero chemical damage to surfaces and plant equipment.
  • The Ultra violet system delivers a  controlled environment of zero corrosion - provides a beautiful water quality perfect for human use, is completely safe for young children.

Ease of Use:

  • Chemicals need testing, which requires knowledge. 
  • The Ultra Violet system is non-chemical = no testing.
  • Installed in the plant room on the return line to the pool. As long as the water is circulated the UV system is active and affective.
  • The longer the water circulates the more effective the UV system and the better the water quality.
  • Ultra Violet combined with Variable speed pump (see related article) is a low cost ultra-effective hygiene solution.


Upgrading to Ultra violet.

The installation involves...

  • Interuption of the water flow from the sand filter before entering the pool.
  • The UV system is fitted in front of the Chloring feeder.
  • The power supply to the UV system is connected to the same contactor as the water circulation pump. UV and water pump are co-ordinated.



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CYA - Reasons why this is so important:


These are the facts....


  • CYA or Cyanuric Acid is sold as a chlorine stabiliser. 
  • It is designed to increase the life of chlorine in sunlight. Therefore is used in outdoor pools.
  • CYA should not exceed 50ppm. If it does it renders chlorine very ineffective. 
  • CYA is present in Trichlor (tablets). 10 parts of chlorine : 6 parts CYA.
  • CYA is present in Dichlor (granules). 10 parts of chlorine : 9 parts CYA
  • CYA once in the water does not go by evaporation. It can only be removed by draining.
  • Liquid Chlorine (sodium hypochlorite) does not contain CYA. It is unstabilised. 
  • If CYA is present in the water and unstabilised chlorine is added it will be reduced in effectivness but will last longer.



  • The lower the CYA value the greater the effectivness of chlorine.
  • Adding calculated levels of unstabilised chlorine daily and multiple times of day reduces the need for CYA.
  • The chlorine level needs to be 7.5% of the recorded CYA level. High levels of chlorine will produce itchy skin, red eye, bleach clothing, and is in any case carsinagenic.
  • Using Ultra Violet technology dramatically reduces the demand upon chlorine by removing bacteria, virus, algae from the circulating water, it also removes the toxic chlorine that forms as a result of oxidation and disinfection. 

Research Data: