ENDURAMAXX Rainwater Harvesting & Filters

Rainwater is part of the never-ending water cycle. Saving water is now an essential part of sustainable society.
Enduramaxx products, with their individual proven designs, are available to meet the widest possible range of uses in rainwater harvesting and management.

Guidelines for some typical applications

One (1) Person 50/ day 250/ day
Two (2) Persons 80/ day 360/ day
Three (3) Persons 145/ day 435/ day
Shower 200/ hr 15/ min
Fill Bath 30/ day 140/ ltrs
Flush Toilet 1 to 3 gal 5 to 15 ltrs
Sprinklers 180/ hr 14/ min
1/2 tap at 20psi 600/ hr 55/ min
3/4 tap at 20psi 1000/ hr 75/ min
Cattle per day 10 to 20 45 to 90/ day
Milking Cows 30 to 40 135 to 180/day
Sheep/ Pigs 1 to 2 4 to 9/ day


Choosing your tank volume
It is particularly important to ensure that your system fully meets your requirements and options, In general you should collect as much rainwater as possible. You can use Enduramax’s ‘rule of thumb’ for the initial rough calculations as follows:
Guidelines for some typical applications

For each person, you need a tank volume of at least 1500 litres. For a tank volume of 1000 litres, a roofed surface of 15m2 is necessary. More detailed calculations are available in the following table:


Systems for domestic supply and garden irrigation

1-2 50 Yes Yes 50 4000
2-3 80 Yes Yes 100 5500
3-4 100 Yes Yes 200 7000
4-6 120 Yes Yes 400 9500
6-7 >160 Yes Yes 800 12000


Rainwater Utilisation

Three stage cleaning process
With good planning and the right components a rainwater system can be nearly maintenance free and the rainwater quality is ideal for many uses, in both the home and the workplace. A professional system will have three stages of cleaning.

Roof areas
Only rainwater from roof areas should go into the storage tank. Smooth surfaced materials are the best (slate, tiles, glazed, cement, roofing slab). The rain yield from green roofs is 30-50%  and whilst it can sometimes be a bit discoloured it is still suitable for toilet flushing and garden watering.

Cleaning step 1- Filter
The first cleaning step in the rainwater system is the filter. The rainwater flows from the roof to the filter. Here, dirt particles and debris are separated from the water. The cleaned water flows to the tank. The dirt is washed to waste or soaked away with a small amount of rainwater.  All rainwater filters have colters, which are easy to remove and easy to clean. Their many different working principles and connection possibilities allow for their use in many different installation situations.

Cleaning step 2-Calmed Inlet
Here the second cleaning step takes place. In the ater column, any residual particles settle to the bottom of the tank. The rainwater calmed inlet ensures that oxygenated water is introduced to the lower layers of the stored water in the tank. This oxygen rich water prevents anaerobic reducing conditions forming in the storage tank and ensures that the water stays fresh. It also allows water to enter the tank without disturbing the water that is already there.

Cleaning step 3- Overflow siphon
Any particles that are lighter than water (e.g flower pollen) float slowly to the water surface. The overflow siphon, with a skimmer effect, removes the floating layer. The overflow from the storage tank is important to get the optimum water quality. It prevents souring of the water. The floating layer could otherwise build up over time and so reduce oxygen diffusion at the water surface, which in turn could lead to anaerobic reducing conditions in the tank,

RAINWATER HARVESTING How to get started:

1) Decide on the amount of rainwater you will need to have stored in reserve and also the amount of water you will be able to harvest from your roof.
2) Using the water catchment table on the previous page and the average annual rainfall for your area, calculate the amount of rainwater you will capture from your roof area. Add at least 10% capacity for the summer months. Now you can identify the capacity you will require
3) Identify your proposed tanks site and measure the space and height available
4) Refer below for dimensions






0 X H (mm)




17220531+ A, B or C 1250 275 1200 x 1200 1.5"
17221031+ A, B or C 2500 550 1400 x 1800 1.52
17221231+ A, B or C 4000 881 1900x 1650 2"
17221431+ A, B or C 5500 1211 2600x 1320 2"
17221531+ A, B or C 5500 1211 1900 x 2300 2"
17221731+ A, B or C 7000 1541 2400x 1820 2"
17221831+ A, B or C 8500 1872 2600x 2064 2"
17222031+ A, B or C 9500 2090 2400x 2400 2"
17222531+ A, B or C 12000 2643 2600x 2560 2"
17223031+ A, B or C 16000 3555 2600x 3350 2"
17223531+ A, B or C 20000 4444 2600x 4130 2"

5) Choose from the 3 filter kits below A, B or C and place your order.


Kit A: Will service a 200m2 roof area and is better suited to general garden use and yeard washdown. This filter should be cleaned several times a year depending on contamination. 100mm connections, 1mm poly mesh. This kit would generally be used on a tank between 1250-9500 litres.

Code 254010 Rainwater Harvesting Kit A contains filer, siphon overflow, claimed inlet and internal pipe.


Kit B: Will service a 450m3 roof area and is better suited for WC flush and a better quality of water filered, this fileter can also be used for general garden use, vehicle washdown, dairy and much more...This filter should be cleaned twice a year, depending on contamination. 100mm connections, 0.65mm stainless steel mesh. This kit would generally be used on tanks between 5,500-20,000 litres.

Code 254020 Rainwater Harvesting Kit B contains filter, siphon overflow, claimed inlet and internal pipe.


Kit C: Will service an 800m3 roof area and has exactly the same filter mechanism as Kit B- again this filter should be cleaned twice a year. 100mm connections, 0.65mm stainless steel mesh. This kit would generally be used on tanks betwen 5,500-20,000 litres. 

Code 254030 Rainwater Harvesting Kit C contains filter, siphon overflow calmed inlet and internal pipe.  

*All rain water filters are well over 90% efficient, some are at 100%. All filters are hydraulically safe for use in teh UK at the given Connectable Roof Areas (based on a root rainfall intensity of 79mm/hour).



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01295 211 790