Next-day shipping across the entire UK, including islands, started 3rd August!!
Next-day shipping across the entire UK, including islands, started 3rd August!!
Most water fed pole guides bang on about poles, brushes and hose reels. Hardly any mention the one part that actually decides whether your windows come up spotless: the resin. Get the wrong grade, or leave it in too long, and you’ll be back to squeegees and streaks no matter how good your pole is. This guide sorts out di-ionised resin for a water fed pole in the UK, what it is, how much you need, and when to swap it.
Tap water isn’t pure. It carries dissolved minerals and salts that leave chalky spots behind once the water dries on glass. Di-ionised resin strips those minerals out before the water ever reaches your brush.
The resin sits in a canister, usually built into your water fed pole system between the pump and the pole. Water passes through it on its way up to the brush head. The resin does the cleaning work before you’ve even touched the glass.
The resin works through a process called ion exchange. Tiny resin beads swap out the minerals in your tap water, things like calcium, magnesium and other dissolved solids, for hydrogen and hydroxide ions. Those ions then combine to form more water. The result is water with almost nothing dissolved in it.
That “almost nothing” is the whole point. Pure water has no minerals left to dry into spots on the glass. It also carries no soap or chemical residue, so windows dry naturally clean without any wiping. That’s why a pure water setup, resin included, has largely replaced traditional squeegee cleaning on both domestic and commercial jobs. If you’re new to the whole idea, the complete pure water window cleaning system guide covers how the pump, hose, filter and resin all work together.
Not all di-ionised resin for window cleaning is sold the same way. The two main types you’ll come across are mixed bed resin and single-use (sometimes called colour-changing) resin.
Mixed bed resin combines both cation and anion resin beads in one bag. You pour it into your canister and it works straight away, treating your water in a single pass. It’s the simplest option, which is why most domestic buyers go for it.
Single-use resin is often sold with a dye that changes colour as it exhausts. That gives a clearer visual signal of when it needs replacing. Some pros prefer this because it makes it easy to track exactly how much water a batch of resin has treated, which helps with costing jobs.
For a homeowner cleaning their own windows a few times a year, mixed bed resin is the easier choice. It’s straightforward to use and there’s no need to fuss over colour changes or exact treatment volumes.
For a self-employed window cleaner running a system daily, either type can work. Some pros stick with mixed bed and simply check TDS regularly. Others prefer single-use resin for the built-in visual cue, especially when they’re switching between jobs and don’t want to stop and test water constantly.
A TDS meter measures total dissolved solids in your water, in parts per million. It’s a cheap, small device, and it’s the only reliable way to know your resin is still doing its job.
Fresh resin should bring your TDS reading down close to zero. As the resin exhausts, the reading climbs. Testing your water regularly, rather than waiting for spots to appear on the glass, is the difference between a properly finished job and a re-clean.
A TDS meter reading close to zero confirms the water is fully de-ionised. Once that number starts climbing above single figures, spotting on glass becomes more likely, especially on darker frames or in direct sun.
There’s no single number that applies everywhere, because tap water quality varies across the country. The safest approach is to test before every job, or at the start of every day if you’re cleaning professionally. When the reading creeps up from where it normally sits, it’s time to change the resin. Don’t wait until it’s obviously failing.
Hard water areas of the UK, such as much of the South East, tend to exhaust resin faster than soft water regions like parts of Scotland and Wales. If you’re in a hard water area, expect to change resin more often and budget for it.
How much resin you get through depends almost entirely on two things: how hard your local water is, and how often you’re using the pole.
Resin refills typically come in small bags for domestic use and larger bags for trade use. A homeowner cleaning windows a few times a year will get many months out of a small resin bag. A self-employed window cleaner running a system daily may need to swap resin every few weeks, depending on local water hardness.
If you’re only cleaning your own house a handful of times a year, there’s little point buying a bulk trade-sized bag. It’ll sit around long after you needed it. If you’re on the tools daily, a larger refill works out far more practical than repeatedly buying small bags.
The real comparison isn’t bag price, it’s cost per litre of water treated. A bigger bag usually costs more upfront but treats far more water per pound spent. That makes it cheaper in the long run for anyone using their pole regularly.
For a self-employed window cleaner, buying resin in bulk is almost always the cheaper refill option once you account for how often the canister needs topping up. Anyone weighing up equipment costs more broadly might find it useful to look at the equipment guide for self-employed window cleaners alongside this.
Resin and filters do different jobs, and most water fed pole setups use both.
A filter sits earlier in the system and removes sediment, rust particles and chlorine from your tap water before it reaches the resin. Without a filter, that debris and chlorine can clog or degrade your resin faster. That means you’ll be buying refills more often than you need to.
Resin then handles the de-ionising, stripping out the dissolved minerals that filters can’t touch. Skip the filter and rely on resin alone, and you’ll wear through resin bags much quicker, especially in areas with harder or dirtier mains water. For a full breakdown of how filters work alongside resin, it’s worth reading up before you order either.
Search for resin on Amazon or eBay and you’ll find dozens of listings with vague grades, unclear bag weights, and no real explanation of what you’re buying or how long it’ll last. It’s confusing even for people who’ve used water fed poles for years.
Paul’s Poles sells resin refills sized for both occasional domestic use and daily trade use, priced to undercut typical Amazon and eBay listings. Each refill is clearly labelled so you know exactly what grade you’re getting and how it’s meant to be used. No guesswork, no oversized bags you don’t need.
If you’re not sure where resin fits into your wider setup, the water fed pole system guide for homeowners and professionals walks through the whole system, and the full water fed pole accessories guide covers everything else you might need alongside it. If you’re just starting out, the beginners guide to water fed pole kits is a good place to check you’ve got the right kit before buying resin at all.
Check your TDS meter reading, work out how much water you actually treat in a typical week or month, and pick the refill size that matches. It’s a cheaper, simpler way to buy resin than sifting through mismatched marketplace listings, and it means fewer surprises when your next job needs spot-free glass.
