How to Make Purified Water for Window Cleaning?

For many, using pure water to clean windows sounds fancy, expensive or even complicated! But here’s why it’s one of the best options for you as a window cleaner or client.

The Benefits of Using Pure Water!

First of all, purified water free is eco-friendly and so does not harm the environment or corrode your window seals and rubbers. Moreover, one of the biggest benefits of a pure water system is not having to repeatedly use ladders. Therefore you don’t have to risk your safety each and every time you scale a height. 

Additionally, as a customer your windows will look cleaner for longer, as the pure water flushes all dirt from your windows, frames, sills and PVC doors. Thus, you’ll receive a valet style clean each time your window cleaner comes. Moreover the chemical ability of pure water means the water droplets can be left to air dry leaving no spotting or streaks, saving you valuable time! We all know in this industry that time is money, therefore the quicker and more efficiently you can undertake a job, then the more you can fit into a day’s work!

Pure Water - What You Need?

Pure Water - Step 1

To begin with you will need to test how “hard” the water is where you live. Fill up a glass of water from your tap and using a TDS metre, insert it into the glass to measure it. The reading on your metre will determine which method is best for you.

For example if your metre reads around 120 and below this is good as you have relatively “soft water” meaning you only need a DI vessel and resin to make pure water. Connecting your water source to the DI vessel will push the water through the canister, allowing the resin to filter all impurities and release purified water the other end. For window cleaning, Pure Water need to measure 0.07 or below on your TDS metre, as anything above will cause spotting on windows.

TDS Meter
DI Vessel - 11 Litres


Pure Water - Step 2

If your tap water measures above 150+ then you most likely live in a “hard water” area meaning it has a lot of salts, minerals, and impurities in it. Consequently, you will require a Reverse Osmosis System to filter your water through, removing and capturing any contaminations. Be sure to test the water again using your TDS metre insuring its below 0.07. If not, then you will also need to filter the water coming out of the RO system through a DI vessel filled with resin to finally bring the TDS down.

Merlin Pentair RO system

A garden Set up usually consist of having your osmosis system connected to your outdoor tap. When choosing where to put your RO system you will need to take into consideration where the closest drain is to allow the wastewater to drain away. Alternatively you could buy a long enough hose to reach the drain allowing you to place your RO system where you please, preferably inside a shed or garage.

Pure Water Set Up! - Garden or Van?

When choosing to make Pure water you have to consider what set up is best for you. Some window cleaners have their reverse osmosis system or DI vessel configured within the van, whereas others choose to have it in a garden shed.

IBC Tank - 1000 Litres

For this reason many window cleaners with large rounds prefer to store their pure water in a storage tank first. Most use a IBC tank which is 1000 litres to store all of their freshly made water and then pump it to their van using a submersible pump. Be sure to purchase a powerful submersible pump atleast 750/1100w with a hose of around 1” thick for fast filling up.

Secondly you will need somewhere to store your newly made pure water. Some window cleaners choose to directly connect it to their tank within their van and leave it to fill up overnight. Of course with this kind of set up you have to be careful of over filling your tank and flooding your van. We suggest attaching a water timer to your tap where you can set the period of time you want the water to flow. Moreover your also limited to how much water you can make at one time, for example if you have a 500 litre tank you can only make 500 litres.

Submersible Pump

Pros – Filter in your Garden

  • Water can be made in advance and stored
  • You can use your van while the water is being made
  • Less chance of freezing if stored in a shed

Cons – Filter in your Garden

  • Storage tank takes up a lot of space
  • Need a submersible pump to transport water to Van
  • Need a drain to dispose of wastewater

Filtering Pure water in your van!

Not everyone has the money upfront or the space to have a garden set up. For this reason, having your RO system or DI vessel configured in your van may be more suitable to your circumstances.

This means you can fill up your tank with normal water wherever you are, and it will automatically convert it into pure water to use straight away. As long as you have a water source nearby you can never technically run out of pure water when on the job. However, having such a set up means you are dependant on the water pressure from the tap. Without sufficient pressure your RO system may not work or take longer then usual to pump out pure water (you will need a booster pump if that is the case). Furthermore, the added weight of having a van system set up may reduce the amount of water you can safely carry in order to keep to your vans recommended payload.

Mounted RO system with 2 membranes, connected to a DI vessel
Self-service Pure water filling station

Limited Funds?

If your budget doesn’t allow for a Reverse osmosis system or Di vessel set up, then the best way to get started is to simply purchase your pure water from a filling station.  

Filling stations provide pure water relatively cheap allowing you to fill up your tank or jerry cans. Consequently you don’t have to spend a lot of money in the beginning to get started. Of course making your own water may work out cheaper in the long run and be more convenient.

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