What Happens If You Combine a Salt-Based Water Softener With an Aquabion?
Belt-and-braces limescale protection for Andover, Marlborough & Hungerford homeowners — is it worth using both systems together?
By Will at Rosebourne Plumbing | February 2026 | 15 min read
If you live anywhere around Marlborough, Andover, or the Hampshire/Wiltshire border, you already know the score. Our water is rock hard. Limescale in kettles, white residue on taps, and heating elements that fur up faster than you would like. Most people have heard of water softeners. Some have come across the Aquabion. But what happens if you use both at the same time?
It is a question I get asked more than you would think, so let me break it down properly. No jargon, no sales pitch — just what I have learned from installing and maintaining both systems across properties in Andover (SP10/SP11), Marlborough (SN8), Hungerford (RG17), Great Bedwyn, Tidworth (SP9), Pewsey (SN9), and Stockbridge (SO20).
Quick Answer: Yes, you can use both together — and done correctly, it gives you the best of both worlds. The salt softener handles the hot water circuit where limescale does the most damage, while the Aquabion conditions the cold drinking water, keeping beneficial minerals intact. Keep reading for the full breakdown.
How Does Each System Actually Work?
Salt-Based Water Softener
A traditional water softener uses ion exchange. Hard water flows through a resin bed, and the calcium and magnesium ions (the stuff that causes limescale) get swapped out for sodium ions. The result is genuinely soft water — the minerals are physically removed.
Trade-offs: Needs regular salt top-ups, requires electricity, produces waste water during regeneration. Some environmental concerns around brine discharge. Adds sodium to water — a separate drinking tap is usually recommended.
Aquabion Water Conditioner
The Aquabion takes a completely different approach. It is a compact, inline unit that uses a galvanic zinc anode — no electricity, no salt, no chemicals, no magnets. As water flows through, a tiny electrical charge builds naturally between the brass casing and the zinc core, releasing trace zinc ions.
How it works: Zinc ions act as seed crystals, converting calcium carbonate from calcite (the sticky stuff that clings to pipes) into aragonite — a softer, powdery form that stays suspended rather than sticking to surfaces.
The Key Difference
A softener removes the minerals. An Aquabion changes their behaviour. The softener gives you genuinely soft water (slippery feel, no scale at all). The Aquabion gives you conditioned water (minerals still present, but they do not stick to surfaces). Both reduce limescale — but through completely different mechanisms.
So What Happens When You Use Both?
In short: you get belt-and-braces limescale protection. But there are some things worth understanding before you go down that road.
Recommended Dual-System Layout
Cold Mains Supply
Aquabion Conditioner
- • Kitchen cold tap (drinking water)
- • Outside tap
- • Cold bathroom taps
- • Toilet cisterns
Mains Stopcock
Split after entry point
Key: The split happens after the mains stopcock. Cold supply goes through the Aquabion. Hot feed goes through the softener before reaching the cylinder.
Hot Water Circuit
Salt-Based Softener
- • Hot water cylinder / unvented system
- • Heating system
- • Showers and hot taps
- • Dishwasher and washing machine
Why This Setup Makes Sense
Hot water is where limescale does the most damage
Immersion elements, heat exchangers, and unvented cylinders all suffer badly in hard water areas. A softener fully removes the minerals, giving maximum protection where it matters most. In our area, I have seen immersion elements fail in under 3 years without treatment.
You keep the minerals in your drinking water
Calcium and magnesium are actually beneficial — they are good for your teeth, bones, and cardiovascular health. By conditioning (not softening) your cold drinking water with the Aquabion, you get limescale control without stripping out the good stuff.
You avoid drinking sodium-enriched water
Some people, particularly those on low-sodium diets, prefer not to drink softened water. This setup sidesteps the issue entirely — no need for a separate bypass tap on the kitchen cold.
Reduced salt usage and running costs
Since the softener only treats the hot circuit (not the entire house supply), you use significantly less salt. Typical whole-house softening uses 20-25kg of salt per month. Hot-circuit-only might use 10-15kg — saving you £40-£80 per year.
The Combined Benefits at a Glance
Things to Be Aware Of
I always give the honest picture, so here are the considerations before committing to a dual setup.
Cost
You are buying and maintaining two systems. Total installed cost ranges from £2,000 to £4,000. For many homes, one or the other will do the job perfectly well on its own. A combined system is best justified when you have expensive hot water equipment (unvented cylinders, high-end shower systems) and genuinely very hard water.
Plumbing Complexity
The plumbing needs to be set up correctly — softener on the right circuits, Aquabion on the cold mains, with appropriate bypasses and isolation valves. Get it wrong and you are either softening water you do not need to or conditioning water that is already soft. This is not a DIY job.
Overkill for Some Properties
If your water hardness is moderate (under about 200 ppm), you probably do not need both. Some villages in the Hungerford (RG17) area have slightly lower hardness than central Marlborough or Andover. Get your water tested first and make a decision based on the numbers, not assumptions.
Head-to-Head Comparison: Softener vs Aquabion vs Combined
Here is how the three options stack up across the metrics that actually matter for properties in the Andover, Marlborough, and Hungerford areas.
| Feature | Salt Softener | Aquabion | Combined |
|---|---|---|---|
| Removes minerals? | Yes - fully | No - changes their form | Hot water: yes / Cold: conditioned |
| Scale protection | Excellent (100%) | Very good (80-90%) | Maximum protection |
| Installed cost | £1,500-£3,500 | £300-£500 | £2,000-£4,000 |
| Annual running cost | £150-£250 | £0 | £50-£80 (salt only) |
| Maintenance | Regular salt top-ups, servicing | None for ~7 years | Salt top-ups only (reduced) |
| Drinking water quality | Sodium added (bypass tap needed) | Minerals retained | Minerals retained naturally |
| Environmental impact | Brine discharge, salt production | None | Reduced (less salt used) |
| Water feel | Slippery, soft feel | No noticeable change | Soft hot water, normal cold |
| Equipment lifespan | 15-25 years | ~7 years (then swap anode) | Both at their rated lifespans |
| Best for | Very hard water, unvented systems | Eco-conscious, low-maintenance | Maximum protection + health |
Full Cost Breakdown
Here is what you are actually looking at in terms of outlay and running costs. These are real-world figures based on installations I have carried out across the Andover, Marlborough, and Hungerford areas — not manufacturer estimates.
Aquabion Only
Fit and forget
Salt Softener Only
Whole-house treatment
Combined System
Hot softener + cold Aquabion
The Surprising Cost Advantage
A combined system can actually cost less to run over 10 years than a whole-house softener alone. Because you are only softening the hot circuit, salt usage drops by 40-50%. The Aquabion has zero running costs. And you avoid the expense of installing a separate drinking water bypass tap. For properties in Andover (SP10), Marlborough (SN8), and Great Bedwyn (SN8) where hardness regularly exceeds 300 ppm, the combined approach often makes the most financial sense.
Which One Should You Choose If You Only Want One?
If budget or simplicity means you want just one system, here is how I would think about it based on the properties I work on across the Andover, Marlborough, and Hungerford areas.
Go With a Salt Softener If...
- You have an unvented hot water cylinder (e.g. Megaflo, OSO, Telford)
- Your water hardness exceeds 300 ppm (most of SP10, SP11, SN8)
- You have expensive shower systems or bathroom fittings worth protecting
- You want guaranteed 100% limescale removal
- You suffer from eczema or dry skin (soft water clinically helps)
- You are prepared to manage salt top-ups and occasional servicing
Go With an Aquabion If...
- You want a fit-and-forget solution with zero ongoing costs
- You prefer to keep beneficial minerals in your drinking water
- You are environmentally conscious (no salt, no brine, no electricity)
- Your water hardness is moderate (under 300 ppm)
- You are on a tighter budget for the initial outlay
- You do not want the "slippery" feel of softened water
Hampshire, Wiltshire & Berkshire: Local Water Hardness Guide
Our area sits on the Hampshire/Wiltshire/Berkshire chalk, which means our water is drawn from chalk aquifers. The geology gives us mineral-rich water that is excellent for health but brutal on plumbing. Here is what I typically recommend based on where you live.
Andover (SP10/SP11) & Tidworth (SP9)
Including Upper Clatford, Shipton Bellinger, Bulford, Durrington
Recommendation: Combined system strongly recommended. Salt softener on hot circuit is almost essential for protecting unvented cylinders and showers. Aquabion on cold mains to keep drinking water natural. At these hardness levels, a conditioner alone will struggle to keep up.
Marlborough (SN8) & Great Bedwyn (SN8)
Including Ramsbury, Aldbourne, Burbage, Savernake, Mildenhall
Recommendation: This is our home village area and we see the hardest water of all — some properties in Great Bedwyn test over 380 ppm. A softener is virtually essential here. The combined setup gives maximum protection and avoids the sodium-in-drinking-water concern that many homeowners raise.
Hungerford (RG17)
Including Lambourn, Great Shefford, Inkpen, Kintbury
Recommendation: Slightly lower hardness in some Hungerford villages means an Aquabion on its own may do a decent job for everyday use. If you have an unvented system or high-end fittings, add a softener on the hot side. Otherwise, an Aquabion is a sensible starting point.
Pewsey (SN9) & Stockbridge (SO20)
Including Upavon, Woodborough, King's Somborne, Houghton
Recommendation: Similar story to the Andover area. Properties near the river valleys may have slightly different hardness depending on the water source. Test first, but expect to need at least a softener on the hot side for reliable protection.
Free Water Hardness Testing
Not sure what your water hardness actually is? I carry a test kit in the van and I am happy to check your water when I am in the area. It takes two minutes and costs you nothing. The numbers will tell us exactly what system (or combination) makes sense for your property. Get in touch or call me on 01264 502027.
My Honest Take
Will Gaze, Rosebourne Plumbing
Professional plumber serving Andover, Marlborough & Hungerford
For most homes in our area, either system on its own will make a noticeable difference. If you have got an unvented hot water system or a high-end bathroom install, I would lean towards a softener on the hot side as a minimum — the protection it gives your cylinder and fittings is worth the investment. I have seen too many immersion elements and expansion vessels fail prematurely because of unchecked limescale.
If you want a fit-and-forget solution with no ongoing costs and you are happy with conditioned rather than softened water, the Aquabion is a brilliant bit of kit. WRAS-approved, no moving parts, and genuinely effective. I have installed them in properties across Great Bedwyn, Ramsbury, and Aldbourne where they have performed well for years.
And if you want the full package? Combining the two — softener on hot, Aquabion on cold — gives you the best of both worlds. Just make sure it is installed properly. The plumbing layout matters, and getting the circuits wrong defeats the purpose of running two systems.
If you are not sure what is right for your home, give me a shout. I am happy to test your water hardness and talk you through the options — no hard sell, just honest advice.
Frequently Asked Questions
1Can you actually use a water softener and Aquabion at the same time?
Yes, absolutely. The most effective setup is to run the salt-based softener on your hot water circuit (cylinder, heating, showers) and the Aquabion on the cold mains supply (kitchen tap, outside tap, drinking water). They use completely different technologies and complement each other well when plumbed correctly.
2How much does a combined softener and Aquabion system cost to install?
A combined system typically costs between £2,000 and £4,000 installed, depending on the softener brand and the complexity of your pipework. An Aquabion alone runs £300-£500 installed, and a quality salt softener ranges from £1,500-£3,500 installed. You also save on ongoing salt costs since the softener only treats the hot circuit.
3Is a combined system overkill for my Hampshire home?
It depends on your water hardness and property. In areas around Marlborough (SN8) and Great Bedwyn where hardness regularly exceeds 350 ppm, a combined system makes genuine sense, especially if you have an unvented cylinder or expensive bathroom fittings. For moderate hardness (under 200 ppm), one system on its own usually suffices.
4Will the Aquabion affect softened water if they overlap?
If installed correctly, they should not overlap. The softener handles the hot circuit and the Aquabion handles the cold mains. If softened water does pass through the Aquabion, no harm is done, but there is no additional benefit either since the minerals have already been removed by the softener.
5What are the annual running costs of each system?
A salt-based softener on the hot circuit only costs roughly £50-£80 per year in salt (less than whole-house treatment) plus around £50 for electricity. The Aquabion has zero running costs for its entire 7-year lifespan. A combined system is typically £50-£80 per year total, which is actually less than running a softener on the whole house.
6Do I need a separate drinking water tap with a combined system?
No, and that is one of the main advantages. Because the Aquabion handles the cold mains, your kitchen tap delivers conditioned water with the beneficial minerals (calcium and magnesium) still present. You avoid both the sodium from softened water and the expense of installing a separate bypass tap.
7How long does each system last before needing replacement?
The Aquabion has a service life of approximately 7 years before the zinc anode needs replacing (around £300-£400 to swap). A quality salt-based softener (Harvey, Kinetico, BWT) can last 15-25 years with proper maintenance. So over a 20-year period, you would replace the Aquabion roughly 3 times.
8Can Will at Rosebourne Plumbing install a combined system?
Yes. We install both Aquabion water conditioners and salt-based water softeners across Andover (SP10/SP11), Marlborough (SN8), Hungerford (RG17), Tidworth (SP9), Pewsey (SN9), Stockbridge (SO20), and Great Bedwyn (SN8). We can test your water hardness, assess your property, and recommend the right setup. No hard sell, just honest advice.
Need Water Treatment Advice for Your Home?
Whether you need an Aquabion, a salt softener, or a combined system — I will test your water, assess your property, and give you an honest recommendation. Serving Andover (SP10/SP11), Marlborough (SN8), Hungerford (RG17), Great Bedwyn, Tidworth, Pewsey, and Stockbridge.
Honest work, done properly. No hard sell, just straightforward advice.
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