- Basically a pool is a water storage tank that is also used for swimming.
- The water is circulated via a system of pipes and into a water filtration plant.
- A skimmer box is a pre cast plastic bucket like weir that is set into the pool wall during concreting stage.
- The skimmer box has a window opening facing into the pool and usually a front weir flap.
- The skimmer is set at a height that enables the water level to be approximately half way up the window.
- Water flows into the skimmer box and then travels in the suction line away to the filter.
- The skimmer box is designed to draw water from the surface and collect floating dust and leaves etc.
- Inside the skimmer box is a leaf trap basket to catch leaves and other floating items.
- There is a safety lid which opens from the top of the skimmer to enable access to the basket.
- Modern skimmers in concrete pools are very safe for children and the lid can be locked down if required.
- Skimmer lids are available in a range of colours to match paving or decking that forms the pool surrounds.
- Some larger home pools may require two or more skimmer boxes based on a suggested formula of one skimmer for every 30m2 of pool surface area.
- For pool locations with lots of trees we advise extra skimmer boxes and hence more leaf traps.
- One of the regular pool jobs is to clean out the basket.
- You can train your kids to do that.
- Water resistance in pipes reduces as the pipe diameter increases.
- If the water resistance is too high you will be wasting energy and increasing your power bill.
- Most household pools have a 50mm suction line from the skimmer boxes to the pump.
- Also extra bends in the pipes add to the resistance so a short straight suction line pipe is the best for water flow.
- The circulation pump is located in the pipework before the filter.
- The water is pushed into filter by the pump.
- The pump has a hair and lint pot with another basket to catch smaller rubbish before it gets to the filter.
- After passing through the filter and sterilization system, such as a salt chlorinator, the water returns to the pool in 40mm or 50mm pipework.
- The size of the pipe depends on the filtration pump size.
- The pump is selected by the pool builder based on the water flow that it creates and the time to circulate all of the pool water.
- In my experience we try to circulate the entire pool in a 6 hour period or less.
For the academics: a simple formula is
- (Pool volume in litres) divided by 4 hours divided by 60 minutes = flow rate /minute.
- We expect a Zodiac 1.0HP pump to circulate 300 litres/ minute.
- Putting a bigger pump on the system will not flow any better without also upgrading all of the pipework diameter.
Adjustable pool return eyeballs
- Your pool designer will locate the water returns positions hopefully towards the skimmer boxes to assist with surface skimming.
- The number of return eyeballs is a function of pool shape and even prevailing winds.
- The eyeballs are just under the water level and the direction can be adjusted from inside the pool.
- Most eyeballs are white plastic however for people who like a bit of BLING, stainless steel eyeballs are available at an extra cost.
Heater pipes just for the heater
- I believe the most efficient heating method is to have the heater and the filter system on separate plumbing lines.
- The pump, filter and chlorinator sterilize the water and are usually activated during pre-set times such as the morning and evening.
- The heater however with a timer and thermostatic control operates when the temperature switch activates the heater. The running times obviously can be different.
- Pool water is colder at the deepest section
- Therefore heater pipe suctions are placed lower in the pool wall than the surface eyeball returns.
- The cold water is then circulated to the heater and then also returns to the lower section of the pool.
- Science says hot water then rises to the top and hopefully provides an evenly heated pool.
- Heater pipes installed in the pool shell at concrete stage can enable future heater installation without having to dig up the pipes.
- Heater pipes safety suctions have to be greater than 1.0 m apart so people cannot get caught in the suctions.
- Heater pipes usually have two suctions and two returns so you will have two more eyeballs and two safety suction covers.
Standard equipment location
- The pumps and filters are best located more than 3.5 m from the pool and hopefully less than 10m.
- Longer suction lines may require larger diameter pipes and more powerful pumps and extra costs.
- Filter location is one of the first items covered in our initial design interview.