Why Filtering Rainwater from Roofs Is Important

Filtering rainwater from roofs are required for rainwater tanks for homes, agriculture, office and another commercial as storing rainwater can reduce water and sewage bills, water the garden during a hosepipe ban, used for toilets and commercial uses such as dust suppression and cooling.  Using rainwater in agricultural sprayers can also reduce the use of chemical conditioners.

When collecting rainwater from your roof it is important that it is filtered before goes into the tanks so that it is as clean as possible.  This will help prevent the water from going smelly before you use it.  Rainwater harvesting systems, whether the water is stored in water tanks above ground tanks or one buried in the ground, there are four main components you need if you want to use the rainwater in non-potable situations like; toilets, washing machines, vehicles, watering the garden or irrigating.

These steps shown here are explained in more details:

  1. Filter the water from leaves & moss before it enters the water tank
  2. Oxygenating the water as it fills
  3. Siphon off floating particles
  4. Fit an inline suction filter before pumps and pipework

Even for farmers using the water for spraying crops – filtering the water will help in the long run.  For using this water for drinking, further steps such as disinfection are required.

The four-step rainwater cleaning process uses the flow of the water and the water in the tank to always use the cleanest rainwater.   With many rain harvesting storage installations providing the water is filtered, and the tank cleaned regularly from silt, chemicals will rarely be required and you won’t get the smelly water or brown water stains associated with incorrectly filtered rainwater.

For long term water storage for agriculture application for agricultural sprayer water storage, you may need to use some chemicals.  For these installations requiring chemical, we recommend contacting a rain harvesting installer to ensure filters and dosing equipment are suitable for the intended outcome.

Step 1 – Filter the water from leaves & moss before it enters the water tank

Filtering the water is the most important step and we recommend this in every rain harvesting system. By stopping leaves and moss from going into the tank will result in better water quality for the tank whether it be a domestic garden water butt or slimline rainwater harvesting tank of agricultural water tanks for sprayers or industrial rainwater collection system.

Rainwater filters are important to make the water used in any rainwater harvesting system and are used to filter debris from the rainwater as it flows from the collection roof before it enters the storage tank. These filters have an overflow on the 450m2 and 800m2 roof area filters to take out larger debris like leaves, small sticks and moss through an overflow and back down the drain and ensure these don’t go into the water tank.

Filters are sized according to the size of the roof you are collecting rainwater from. Fitting too small a rainwater filter will result in the system working ineffectively and could flood the filter resulting in not as much water being collected as it could do with a correct size filter.

Our larger 450m2 and 800m2 rainwater filters have a stainless-steel mesh and access to the screen to carry out maintenance or cleaning. Installing the rainwater filter where it is easy to inspect for maintenance is essential as all filters need maintenance/cleaning from time to time.

View how much rainwater falls where you live on the MetOffice website here

Step 2 – Oxygenating the water as it goes into the tank

The calmed inlet helps keep the rainwater oxygenated while it is in the tank and this process helps stop the water from going smelly.   The calmed inlet is designed to help the water flow without stirring up any silt or small particles which may have fallen to the bottom of the tank in the water.

As the water flows down the pipe into the tank, the water is funnelled up to the top of the tank oxygenating the water in the main body of the tank without disturbing the settled debris. A calmed unlet is recommended for water tanks over 2,500 litres.

Step 3 – Siphon off floating particles

Particles such as pollen which are finer than the mesh in the filter mesh and lighter than water will float on the top of the water in the tank. A siphon overflow is designed to be fitted at the top of the tank and skim of debris such as pollen etc. This will also act as an overflow for the tank when the tank is full, and it continues to rain.  Generally, these are piped up to the waste from the filter and sent to drain.

As with a calmed inlet, a siphon overflow is recommended for water tanks over 2,500 litres.

Step 4 – Fit an inline suction filter before pumps and pipework

Fittings a suction filter for your rainwater tank is important because if you are pumping the rainwater for use in the garden, agricultural or commercial situation particles that are smaller than the mesh could be sucked through.

Enduramaxx Rainwater Harvesting Kits

Enduramaxx rainwater harvesting filter kits are sized according to the roof area you are collecting from, these filters whilst prevent moss and leaves going into your rainwater harvesting tank, allow you to take advantage of the free rainwater, soft water. These kits include the basket filter or self-cleaning design, these filters suit every roof size whether it is a domestic house, an agricultural barn or a commercial factory.

To discuss your next rainwater project, why filtering rainwater from roofs is important or pricing and availability of tanks please contact us today or email sales@enduramaxx.co.uk

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