How To Use Mixed Bed Resin to Clean Windows – Tips & Tricks

How To Use Mixed Bed Resin for Window Cleaning

I have spent a number of years in a window cleaning business using mixed bed resin to help me clean my client’s windows. Before using mixed bed resin, I used to do everything with a squeegee. Now I find that using mixed bed resin with a pure water system is by far the most cost effective and productive way to clean windows. So how do you use mixed bed resin for window cleaning?

To clean windows using mixed bed resin you will need a DI tank to hold the resin with an inlet and outlet for tap water to enter and pure water to exit. The mixed bed resin will remove ions from the water that cause water spots, leaving only pure water. The pure water is fed through a water-fed system that exits through jets in a brush. As the brush agitates and lifts the dirt from the window the pure water washes it off leaving it to dry spot-free.

Well, that’s the simple answer, now let’s show you how to do it all step by step with tips to get the best clean for your windows.

When I first started window cleaning using pure water there wasn’t a lot of information out there to help you with issues that I encountered while using the mixed bed resin. Some of these issues were smearing or streaks on the tops of windows and how to prevent them from occurring. I also found it difficult even to just find an easy way to get the resin into my tank, and when it had been used, to get it out of the tank. So I will go into detail in this article to help you with many of the problems that you will encounter.

How To Set Up The Pure Water Fed System For Window Cleaning

First you will need some mixed bed resin that is a strong acid cation and a strong base anion, as this is best for purifying the water that you will be using to wash down the windows.

For an explanation of how the mixed bed resin works please check out our article: What is Mixed Bed Resin & How Does It Work?Opens in a new tab.

The first mistake I made was to have a low-grade resin that wasn’t a strong acid cation and strong base anion. The water wasn’t pure enough so I didn’t get a completely spot-free finish.

The reason was that there were still a lot of dissolved salts left after the water had passed through the resin. My TDS reading was 10 ppm to 15 ppm rather than 0 ppm. It’s important to note that window cleaning can be done with water at 10ppm or less, whereas at 10 ppm or more you will start to see spots.

I didn’t want to waste my poorer grade resin so I devised a way to use it and still get 0 ppm.

If you have a low-grade resin, I suggest you do the same. Buy a bag of good strong acid cation and strong base anion that will give you a 0 ppm TDS reading and use this in the bottom of your DI tank.

You only need a couple of litres. Then fill the rest of your tank up with the lower grade resin. As the water passes through the low-grade resin it will take the TDS reading down to ppm then as the water hits the high-grade resin it will polish it down to 0 ppm.

There you go, since the low-grade resin is doing most of the work, the few litres of high-grade resin used like a polisher does less work and lasts longer yet I still get 0ppm water to get a good spot-free finish.

Fortunately, all of my mixed bed resin is now strong acid cation and strong base anion resin, so I don’t need to use a polisher. If you want to read the full story please check out our article: How and Where To Get The Best Mixed Bed Resin For Window CleaningOpens in a new tab.

If you don’t have any mixed bed resin then take a look at our 25-litre bags of mixed bed resin in our store. It’s a high-grade strong acid cation and strong base anion mix that will give you a TDS reading of 0 ppm. Click here to buy our mixed bed resin. Opens in a new tab.

The next important piece of equipment you will need is a good DI tank to hold your resin. You can get them in different sizes. The smallest I have seen is 5 litres and the largest I have used is 20 litres.

I recommend going in the middle for window cleaning. The 5-litre tanks will do but are really too small if you are using it all of the time. You will need to change out your resin more regularly as it will get used up quicker.

I started with a 5-litre tank but now use a 10-litre tank which is perfect for me. It’s not too big and heavy that it’s a mission to pick up and carry to each tap, and not so small that I am having to constantly change the mixed bed resin.

If you are using the pure water system for cleaning cars on a car sales yard then the bigger 20-litre tank strapped to a trolly is best. The trolly just makes it easy to push around the car yard.

DI Tank Sizes for Mixed Bed Resin
DI Tank Sizes for Mixed Bed Resin

I also found that having a prefilter on your tank gives better water quality and a better finish. I use an activated carbon filter and they are cheap to buy. The housing that you put the carbon filter into may set you back a hundred dollars or so, but it is well worth having it. You only pay once for the housing, and then using connectors you can find at any pipe fitting business you can easily connect it to the inlet of your tank.

Your prefilter housing should have an inlet that you can plug a garden hose into. I use a short piece about 2 meters of garden hose that connects the tank to the tap. My tank stays near the tap so I don’t need a long piece of hose. They are all just your normal garden hose fittings you can buy at any DIY store such as Mitre 10.

The hose from my tank is a 30-meter garden hose that is non-kinking. I have two of them and if I need more hose, I just use a small connector to join the hoses together to give me 60 meters, which is more than enough for most jobs around a house or building.

You might want to test your water by turning on the tap and running a little through the tank and into a bucket. Put your TDS meter into the water you collect and take a reading. If it is below 10 ppm, preferably 0 ppm, then you are good to go.

Depending on your equipment you may then connect your water-fed hose, which is a much narrower hose to the end of your garden hose. I have a click on adapter with a valve allowing me to turn the water off and on without having to go back to the tank or the tap.

The smaller hose diameter produces greater pressure so that you can get good flow on higher windows. It also means you use much less pure water, saving your resin.

If you want to use your water-fed hose right from the tank then you can get an adapter to do this. My carbon fibre pole has one of these adapters, which also makes it easy if I want extra length as I can use a general hose connector to join a garden hose to it to give me more length.

What’s The Best Brush To Use For Your Water Fed System for Cleaning Windows

The smaller hose will then lead to a brush where jets of water will exit via special holes in the brush head or via a rinse bar which sits on top of the brush.

If you can’t afford a carbon fibre pole then you can use an aluminium pole that is used for holding a squeegee and screw your brush onto the end using a brush adapter.

This is what I used for years and it worked fine. My pole cost me less than two hundred dollars and was able to extend two stories. My carbon fibre pole is so much better, it is easy to extend and is able to do 4 stories, yet still, fit into my small van.

It’s important to note here that there a number of different brushes you can buy and some are better suited to certain jobs. I don’t particularly like the synthetic nylon brushes.

My personal preference is for the natural boar hair brushes that tucker sell. I actually now use a brush that is a combination of nylon and boar hair called a hybrid brush.

It’s a dual trim brush meaning the outer nylon hairs are longer than the inner set of boar hair. This is great for getting into the corners of windows.

My hybrid brush has four pencil jets that push jets of water out from along the middle of the brush. I also have a rinse bar connected to the top which also allows me to keep the brush on the glass and not have to lift it to rinse the window down. This is a great time saver and means less effort with having to lift the brush off the glass all of the time.

I also use a wagtail wave microfibre mop, which is great for glass that’s not too dirty. It has a rinse bar at the top along with a microfibre pad and is very manoeuvrable to get difficult to reach windows.

There are also easy to attach adapters to extend its reach and angle to get right on top of bay windows from the ground. I use this mop on a few of my jobs and would not be able to handle the job without it.

If your brush does not have a rinse bar then once you have brushed the glass and lifted the dirt and marks you will then need to pull the brush away from the glass about 5cm so that the jets of water are washing the glass without the brush touching the glass and work your way across and down to rinse down the window.

What I like to do is to actually use a normal window cleaning mop with a bucket of water and detergent (and maybe a little bit of titan glass gleam) to really mop the windows first. Then I use my water fed brush to give the window and frames a final scrub and rinse. It does take a little bit longer but leaves such a great finish.

How To Prevent Smears And Streaks with Your Water Fed Mixed Bed Resin System

If you have ever used a water-fed pure water system only to wash down the windows and find that as they dried, they left a smear right at the top then this advice is for you.

To prevent the windows from smearing or streaking when using a pure water fed system its important to really wash and clean the top of the window frame well. If it is not cleaned well, then dirt particles and organic matter that is left on the frame will run down onto the glass as it is drying leaving a smear or streak.

This especially happens when the day is very hot and the glass is very hot. I have always found it easier to wash down windows that leave a nice smear free and spot free finish when the day is cloudy and there is not a lot of direct sun on the glass.

Sometimes you may find that you brush the tops of the frames really well with your water-fed brush only to find that when they dry they still smear. I always use a mop with detergent and run it along the top frame.

It lifts any dirt so that when I use the brush and pure water there is no dirt left at all on the frame so no way the window will smear. If it does then you don’t have to clean the frame again, just quickly brush and rinse the top of the window once more to leave the desired spot-free finish.

Check Your TDS Meter Readings Regularly To Know When To Change Your Resin

Check your water TDS meter readings regularly coming from your tank. When you start to get TDS readings above 10 ppm or start to see spotting as the windows dry then it is time to change your resin. Check out our video below on how to change your resin.

Just a side note, it is best to check the TDS reading at the tap source if you are out of town doing a job in the country. The reading in town may well be 70 ppm but this does not mean that the same reading will be in the country. The house or building may be using an underground bore or spring water that may be rich in minerals and can be very hard with TDS readings above 200ppm.

If this is the case then you have a couple of options.

First you can take with you some of your own water in 20-litre containers and use an electric backpack. You put the water into the backpack and switch it on. It will pump your clean water through the water fed system and since you have already purified it or used rainwater you have no need of the DI tank and mixed bed resin on the job.

We will show you how to easily set up your own backpack for under a hundred dollars in a future article.

The second option you have is to avoid using your water-fed system completely and simply just mop and squeegee the windows. This is easily done especially if the house is a single-story building.

The third option you can try is to Just use your DI tank and mixed bed resin but realize it will be depleted pretty quickly. If you have the money and want to add a RO (Reverse Osmosis) system before mixed bed resin tank then this is another option.

If you haven’t checked out our mixed bed resin then we recommend you take a look at our resin as we feel it is the best mixed bed resin available for window cleaning:


The PerfectWash System has been providing quality ion exchange resin to the public, car sales yards, window cleaners, laboratory and commercial users for water purification purposes. Our team at Perfect Wash provide the right service and information to help you with your water purification needs for cleaning, car washing, window cleaning and industrial and commercial purposes using Mixed Bed Resin. Please read more about PerfectWash and our story by checking our About Us page.

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