Jargon Buster

Welcome to our jargon buster. We know that industry jargon and often be confusing and difficult to understand. In this guide, you will find some standard terms and processes explained in simple terms. If you think we have missed anything or have any further questions, please contact us.


Backpressure is the force your pump needs to overcome to produce a sufficient flow rate. Several factors determine this. These include pipe size, how many elbows and joints you have, the filter, and how high the pump needs to push the water. All of these create friction which the pump must overcome. If the pressure becomes too high, the flow rate of the pump will drop. 

It is therefore essential to maintain the desired level of backpressure. For many pieces of equipment such as heaters and salt chlorinators, constant water flow is vital due to their safety circuits. If the flow rate drops, many of these systems will automatically shut off to prevent overheating or dangerous failure of the equipment. 

Normally you would expect the pressure of your system to be around 0.75 to 1.5 bar. If the pressure rises above this, it could indicate an air leak or that your filter requires cleaning or backwashing. 

The most common cause of increased pressure is due to a dirty filter. If you have a cartridge filter, you will need to clean and rinse or entierly replace the cartridge. For sand filters, you will need to backwash.

Air leaks generally occur on the suction side of the pump. If you have a leak air can be drawn in and pushed through the pipework system and collect in the filter severely reducing water flow. Alternatively, if the pump is below the waterline, it can cause the pump to lose prime and cause damage if not found in time. Another symptom is a noticeable loss of pressure at the pool jets.


To backwash, you will need to stop the pump then place the MPV valve on backwash. Next, run the pump for 30 seconds or until the water is clear in the sight glass. Then run on rinse for 30 seconds and then on waste to drain the dirty water. Place the valve back on filter and your pressure issues should be solved. Backwashing should be done regularly to ensure that your pool is clean and functioning correctly.

Pump Head 

Pump head refers to how much water per hour a pump could deliver to a certain height and is usually measured in meters or feet. For example, a 1HP pump could deliver 12m³/hr to a height of 6m. Here 6m is the pump head. If the height of the head increases, then the pump will be able to deliver less water and will, therefore, be less effective. 

You can calculate the head by adding up all the lengths of pipe in your system including any elbows, turns, valves and couplings. You will also need to add in the rise in elevation from the pool surface to the pump. Once you have added all of this together to will finally know your total amount of head and will be able to size your pump correctly. 

It is important to remember that when trying to get the correct size of the pump, you must consider both the pump head and the flow rate needed. 

Flow Rate

To ensure that your pool water is sanitized correctly, it is recommended that the total volume of water is filtered two to three times per day. This determines the flow rate and is measured in m³/hr. To find this, you will need to consider the length of time you wish to run your pump and the amount of water in your pool. For example, a 2m by 6m pool with a constant depth of 1m contains 12m³ of water. To filter all this water three times in 8 hours, you would require a pump and filter that could deliver a flow rate of 4.5m³/hr. It is essential to match the filter and pump correctly to ensure that your system is efficient. 

Do not be tempted to oversize your pump or filter. By doing this, you could waste vast amounts of electricity and even damage your entire system. Flow rate is also important to consider when using heating (such as a boiler or air source heat pump) and salt or UV chlorination. If you are having trouble sizing your pump and filter, please contact us and our technical team will be able to help. 

Recycled Glass Filter Media (RGFM)

Recycled glass filter media (RGFM) is an alternative filter media to traditional silica sand. RGFM is made from recycled glass and offers several advantages over silica sand. 

The main advantage of using RGFM is that it has a significantly higher surface area than sand. Filtration relies on the amount of surface area you have in the filter. By increasing the surface area, you increase the level of filtration going on in your filter. If you imagine a grain of sand as a 10cm by 10cm sphere and the RGFM as a 10cm by 10cm cube, it is easy to see the RGFM has more surfaces and, therefore, has a larger surface area. This larger surface area allows the RGFM to give you a cleaner and clearer pool than silica sand. The higher surface area also allows you to use around 15% less RGFM than sand. Clumping and channelling are reduced as well, which makes your filter much more efficient. 

Silica sand has cracks and holes along its surface where bacteria can grow. Alternatively, RGFM has a very smooth surface which means bacterial growth and biofilm formation is significantly reduced. The smooth surface also means that backwashing takes less time and is required less frequently. 

RGFM has a longer lifespan than silica sand and as it is made from recycled material is far more eco-friendly. Please note that RGFM is not sharp, the glass is tumbled, cleaned and rinsed before bagging. RGFM comes in several different sizes for different applications. Please check the size of RGFM required before ordering. 

Salt Chlorination 

Salt chlorination is the process of using salt to generate chlorine to sanitize your pool. Saltwater pools are less harsh on the skin and cause less eye irritation. It also reduces the need to store large amounts of chemicals.

Salt chlorination makes use of the electrolysis process. In this process, salt is dissolved in your pool water where it then passes through an electrolytic cell. Here it is split in from sodium chloride (salt) into sodium and chlorine gas. The chlorine gas then dissolves into the water, which then sanitizes the pool water. Eventually, the sodium and chlorine recombine back into salt, and the whole process begins again. 

UV-C Sanitation 

UV disinfection makes use of light at a particular wavelength of 253.7nm. This wavelength of light is a potent disinfectant. This specific wavelength destroys the DNA of bacteria and viruses, leaving them dead and unable to cause harm. The UV-C light can also kill moulds, viruses and algae. We do still recommend using a secondary sanitizer with your pool. This will ensure that any water that does not reach the UV sanitation unit is always clean and safe. However, using the UV-C system, you can reduce your chemical consumption by up to 70%.

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