Start here: what brings you?
You do not need to know anything about water treatment to use this page. Pick the situation closest to yours and you will get a short answer, what to establish before spending money, the options worth discussing and one clear next step. More than one may apply to you, and you can read them all.
What do you want to use the water for?
Answer this before anything else. It is the single question that changes what you need, what it costs and how much evidence you have to gather. The same tank of water can be perfectly fine for one of these and a bad idea for another.
- Drinking and cooking
- The highest bar, and the one you cannot check by looking. Water can be clear, cold and pleasant and still make people ill. This use needs evidence — a laboratory result, or a supply someone else is already testing — and a barrier you can rely on, not a filter you hope is working.
- Garden, toilets and washing the car
- The most forgiving use, and the sensible place to start with any new source. Nobody drinks it, so the questions become practical ones: will it block the irrigation, will it stain the paving, will it harm the plants or the soil over time, and is it kept clearly separate from the drinking water so the two cannot mix.
- Showers, baths and laundry
- In between, and often underestimated. Nobody is drinking it, but people breathe the spray, it touches skin and open cuts, and it sits in warm pipes and a geyser between uses. Hardness and iron show up here first, as scale on the element and stains on white washing.
Most homes end up with a mix: one source for the garden, another for the house, and a single tap in the kitchen treated to a higher standard than the rest. That is normal and usually the cheapest sensible answer. What matters is that you decide it on purpose rather than discovering it later.
Municipal water you are not sure about
Describe the problem precisely before you buy anything: most tap-water complaints are about taste, smell or appearance, and those are solved by a different and much cheaper thing than a safety problem is.
Municipal water in South Africa varies a great deal by town, and it is neither uniformly excellent nor uniformly suspect. Your supplier is required to treat and monitor it, and in most places the water arriving at your meter has been tested far more often than any sample you would ever send yourself. That does not mean nothing can go wrong between the works and your tap, and it does not mean you have to like the taste. The useful move is to separate the two questions: is this unpleasant, or is this unsafe. They have different evidence and different answers.
Establish this first
Four things, none of which costs anything. They decide whether you are shopping for a filter, phoning your municipality, or doing nothing at all.
Whether there is an advisory in force right now
Check your municipality's website or social media before anything else. If they have issued a boil-water notice or a do-not-drink notice, follow it exactly and stop reading buying guides. An advisory is about a specific event and their instruction is the only reliable guidance during it. No household filter is a substitute for one.
Exactly what you notice, and exactly where
One tap or every tap. Hot side or cold side. All the time, first thing in the morning, or only after the water has been off. Whether the neighbours have it too. This is the most valuable information you can gather, and it is free. A problem at one tap is a plumbing problem; a problem at every tap that the neighbours share is a supply problem.
Whether it started, or has always been so
A change has a cause and is worth chasing: new works, a burst main, a repair, a different source in the dry season, or your own geyser or pipes ageing. Something that has been the same since you moved in is usually the character of that supply, and the question becomes whether you want to live with it rather than what went wrong.
Who in the house drinks it
An infant, someone pregnant, an elderly person or anyone whose immune system is compromised is more vulnerable to a water-borne infection than a healthy adult. If that describes your household and you have any real doubt about the supply, that shifts the answer toward asking your supplier and your doctor rather than choosing between cartridges.
What is worth discussing
These are independent options, not a sequence to install. Most homes need one of them, some need none. Each one says what it does not do, because that is usually the half that gets left out.
A carbon filter at the kitchen tap
Chlorine taste and smell, and a general dislike of the taste
By far the most common answer to a tap-water complaint, and the cheapest. Activated carbon adsorbs chlorine and many of the compounds that carry taste and odour, and it is fitted under the sink or on the counter to treat only the water you drink and cook with, which is a tiny fraction of what the house uses.
What it does not do
It does not make unsafe water safe. Carbon is exhausted invisibly — a spent cartridge flows perfectly while removing nothing — so it has to be replaced on the volume its data sheet rates it for. It does not remove hardness, nitrate or salts, and an ordinary carbon cartridge is not a barrier against bacteria unless it carries a tested claim to that effect.
A sediment filter where the water enters the house
Grit, cloudiness or brown water after an interruption
A cartridge in a housing on the incoming line, catching the rust and scale that a repaired or newly re-pressurised main pushes through. It protects the geyser, the washing machine and every tap washer in the house, and it is usually the difference between a nuisance twice a year and a plumber's visit.
What it does not do
It removes particles, and nothing dissolved. Discoloured water that is discoloured because of dissolved iron or manganese will pass straight through it. It also has to be changed when the pressure drop says so; a neglected sediment cartridge eventually starves the house of flow, and past a point it can pass the dirt through in one slug.
A softener for the whole house
Scale on the kettle and shower, spotting on glasses, poor lather
Hard water is water carrying dissolved calcium and magnesium, and it is a comfort and appliance problem rather than a health one. A softener exchanges those for sodium and stops the scale that shortens a geyser element's life. Whether it is worth it depends on how hard your water actually is, which your municipality usually publishes.
What it does not do
Softened water is not purified water, and hardness is not a contaminant. A softener adds sodium in place of the hardness, which matters to anyone on a sodium-restricted diet, and it needs salt and a drain and regenerates on a cycle. Most people who fit one still want a separate carbon filter at the kitchen tap for taste.
A laboratory analysis
A real safety doubt, an unexplained change, or a vulnerable household
The only thing on this page that answers the safety question rather than the comfort question. An accredited laboratory measures what is actually there. Tell them it is municipal drinking water, say what you have noticed and who drinks it, and let them tell you which package to book and how to take the sample.
What it does not do
A result is a photograph of one sample from one tap on one day, and it costs money. For an ordinary taste complaint on a supply with no advisory against it, it is usually not the proportionate first step. It is also not something DWT does: use an accredited laboratory and follow their own sampling instructions, because their bottles and their holding times govern, not any general advice.
What to do next
Write the first list down before you speak to anyone. It turns a vague worry into something a supplier, a plumber or we can actually answer.
Write these down before you ask anyone
- What you notice, in your own words, and whether it is taste, smell, colour or a stain
- Which taps, hot or cold, and at what time of day
- When it started, and what else changed around then
- Whether the neighbours have the same thing
- Your municipality's current notices, and their published water quality report if they have one
- A photo of the water in a clear glass against a white background, and of any stain
If your concern is taste, smell or appearance, there is no advisory in force and nobody in the house is unusually vulnerable, a filter at the kitchen tap is a reasonable and cheap place to start. We sell those through our retail side, The Water Filter Factory. If there is an advisory, or a vulnerable person drinks the water, or the change is unexplained, deal with your supplier and an accredited laboratory first — buying a filter does not answer that question.
Household filters at The Water Filter FactoryRead further
- When the tap cannot be trusted
What actually goes wrong between the works and your tap, and what each symptom usually means.
- GAC versus carbon block for chlorine, taste and odour
The two kinds of carbon filter, and which complaint each one is actually good at.
- Water hardness
What hardness is, why it is a comfort problem and not a health one, and when a softener earns its keep.
- When to replace a filter cartridge (differential pressure, not the calendar)
The one maintenance habit that decides whether a filter keeps working after the first year.
Backup water for outages
Keeping water available and knowing it is fit to drink are two separate projects. Storage solves the first entirely and the second not at all.
This is the most common household water project in South Africa now, and the good news is that the simplest version works well: a tank filled from the municipal supply while it is on, feeding the house while it is off. You are not making new water, you are holding water you already trust. That keeps the treatment question small. What it does not do is stay clean by itself, and the two things people underestimate are how quickly stored water goes stale and how much of the house they actually want the tank to supply.
Establish this first
Anyone who quotes you a tank size from the number of people in the house is guessing. These are the numbers that actually set it.
What you actually want to keep running
This is the decision that sets everything else. Toilets and one cold tap is a modest tank and no pump worth the name. Showers, the geyser, the washing machine and every tap in the house is a different project with pressure, pump and power to solve. Most households find the honest answer is somewhere in between, and deciding it deliberately saves the most money.
How long the outages actually last where you are
Four hours of shedding and a three-day main repair are different problems. Look back at what has actually happened on your street over the past year rather than at the worst story you have heard. Your municipality's outage notices and the neighbourhood group are better evidence than a supplier's brochure.
Where a tank can physically go, and how it gets there
Water is heavy and a full tank is a serious load, so the base matters, the ground under it matters and getting the tank into the property at all matters more often than people expect. A tank has to be reachable for cleaning too. Measure the space, note the gate width, and look at where the incoming supply and the drains actually are.
Whether there is power when the water is off
A pumped system without power is a tank you cannot use. If your area loses both at once, or if you already have an inverter, that changes which arrangement makes sense — including whether a gravity-fed tank on a stand, which needs no power at all, will do what you need for the outlets that matter most.
What is worth discussing
Arrangements, not products, and they combine differently in every house. The last one is not optional anywhere.
A gravity tank on a stand
Toilets, a garden tap and filling buckets, with no power
The simplest thing that works. Height gives you the pressure, so there is nothing to fail and nothing to switch on. For riding out a short interruption with the toilets flushing and a tap to draw from, this is often the whole answer and by far the cheapest.
What it does not do
The pressure is modest and set by how high the tank sits, so it will not run a shower the way the mains does, and it will not satisfy an appliance with a minimum pressure requirement. The stand has to be built for a full tank, which is a structural job rather than a weekend one.
A ground tank with a pressure pump
Keeping the house at something like normal pressure
The usual whole-house arrangement: the tank fills from the municipal line, and a pump takes water from it to the house at a pressure the geyser and the showers are happy with. Done properly it switches over without anyone noticing, which is what most people actually want.
What it does not do
It needs power, and it is a plumbing and electrical job rather than a delivery. The pump has to suit the house rather than the tank, and an oversized one short-cycles and wears itself out. This is the arrangement where using a competent installer stops being optional.
Keeping the stored water fresh
Every tank, without exception
Stored water is not preserved water. The chlorine your supplier put in it fades, and warmth and light let things grow. The arrangement that solves this on its own is one where the whole house draws through the tank all the time, so the contents turn over continuously and nothing stands for weeks. Opaque tanks, screened vents and a closed inlet keep light, dust, leaves and insects out.
What it does not do
A tank that only fills and sits until the next outage is the hardest case, and it needs a cleaning routine and a plan for what you do with water that has stood for a long time. Where a tank feeds drinking water and the contents do stand, a disinfection step at the outlet is the usual answer; what that should be depends on the installation, so ask rather than assume.
Keeping it out of the municipal main
Any tank connected to household plumbing
Stored water must not be able to flow back into the municipal main, ever. This is the part of the job that protects your neighbours as much as you, and it is the part an inspector will look at. Backflow prevention is a plumbing requirement and the device it calls for depends on the arrangement and the hazard.
What it does not do
We are not going to publish a connection detail here, because what is required is set by your municipality's by-law and not by us, and getting it wrong is the kind of mistake that carries a real penalty. Ask your municipality what they require and use a registered plumber. That answer is genuinely local.
What to do next
Write this down and you have an installer's brief. Three quotes against the same brief are comparable; three quotes against three guesses are not.
Write these down before you ask anyone
- Which outlets must keep working, and which you can do without
- How long you want to be able to run without a refill
- The longest and the most common outages you have actually had
- Where the tank can stand, the space available and how it gets onto the property
- Whether you have power during an outage, and whether you have an inverter already
- Where the municipal connection enters and where the plumbing runs
- What your municipality requires for a tank connected to household plumbing
Take that brief to a competent installer for the plumbing and the pump; DWT does not install. What we can help with is the equipment side — what a pump has to do for the outlets you have listed, and what is worth putting on the tank outlet if it will feed drinking water. Bring the list and ask; you do not need a water analysis to have that conversation.
Ask us about the equipmentRead further
- Backup water
The fuller picture on storing water, including what each alternative source needs before it can be drunk.
- When the tap cannot be trusted
What comes through the pipe when a main is repaired and the pressure returns, which is when tanks earn their keep.
- What UV does
If a tank will feed drinking water, this is the honest account of what a UV barrier can and cannot promise.
Rainwater off your roof
Start it for the garden and the toilets, where it is excellent and easy. Treat drinking it as a separate decision with a much higher bar.
Rainwater is the most satisfying household water project because the water is free, the equipment is simple and the benefit is immediate. It is also the one where the gap between how clean it looks and how clean it is opens widest. Water that has run off a roof has picked up whatever was on that roof: dust, leaves, soot, and droppings from birds, rodents and whatever lives in the trees above it. South African studies of household tank water have repeatedly found faecal indicator bacteria in a large share of samples, including tanks that looked perfectly clean. That is not a reason to skip the project. It is a reason to be clear about what you are collecting it for.
Establish this first
Rainwater is the situation where deciding the use first saves the most money and the most disappointment.
What you want it for, decided now
Garden and toilets is a tank, a gutter and a filter basket. Drinking it is a treated system with a barrier you maintain and evidence that it works. The equipment, the cost and the amount of attention it needs differ by an order of magnitude between those two, and starting with the first does not stop you doing the second later.
What your roof is made of and what is above it
A clean sheet-metal or tile roof with nothing overhanging it is the good case. Overhanging trees drop leaves and give birds somewhere to sit; a roof with old paint, treated timber, moss or a chimney above it puts that into the water too. Note the material, the condition and what grows or perches over it, because it decides how much work the collection needs.
How the rain actually falls where you live
South Africa has summer-rainfall and winter-rainfall regions, and much of it is dry for months at a stretch. A big tank does not create water; it only holds what falls. What matters is how long your dry season is, because that is what you are storing across. Your own experience of when it rains is the starting point, and long-run local rainfall figures are published if you want the numbers.
Where the tank goes and how the overflow leaves
The tank has to sit near a downpipe, on ground that will carry it full, and its overflow has to go somewhere sensible — not against a wall, not into a neighbour's yard and not where it will undermine a foundation. Tanks overflow far more often than people expect, because they are full exactly when it is raining hardest.
What is worth discussing
The first two belong on every rainwater installation. The third is a decision, and the fourth is where most of the misunderstanding lives.
Keeping the debris out at the top
Every installation, at the lowest cost of anything here
Gutter guards, a leaf screen at the downpipe and a screened tank inlet. This is unglamorous and it does more for the water than anything else you can buy, because most of what makes tank water bad arrives as solid material that could have been stopped at the gutter.
What it does not do
Screens need clearing, especially in autumn and after a windy spell, and a blocked gutter guard sends the water over the edge instead of into the tank. This is the part of a rainwater system that fails quietly if nobody looks at it.
Diverting the first flush
Any tank you care about the contents of
The dirtiest water of any storm is the first of it, because it is washing the roof. A first-flush diverter sends that portion to waste before the tank inlet opens. It is a simple device, it is cheap relative to the tank, and it noticeably changes what ends up stored.
What it does not do
It has to drain and reset between storms or it does nothing on the next one, and how much to divert depends on the roof. It reduces what enters the tank; it does not make what enters the tank drinkable.
Garden and toilet use, kept separate
Where almost every household should start
Rainwater is genuinely good for this. It is soft, it suits most plants, and it takes a real bite out of a municipal bill in the wet months. Run it on its own pipework, mark the taps clearly so nobody drinks from them by mistake, and keep it physically separated from the drinking water.
What it does not do
Separated means separated: a non-potable line that can be connected to the drinking-water plumbing, even by a hose left in a tank, is the mistake that turns a good project into a health risk. Whether and how the two may interconnect is set by your municipality, and that is worth a phone call before the pipework goes in rather than after.
Drinking it
A separate project, with evidence and upkeep
It can be done and it is done. What it takes is a designed set of steps rather than one device — keeping the debris out, settling and filtering what gets past, and a disinfection barrier last — plus a laboratory result to show it worked and a habit of maintaining it. The design depends on your roof, your tank and what the water is like, so it is a conversation rather than a shopping list.
What it does not do
A clear-looking tank and an installed filter establish nothing on their own. The evidence is a laboratory result on the water as you actually drink it, repeated, because a roof and a tank change with the seasons. Your municipality may also have requirements about using an alternative source indoors, and treating the water does not by itself make a connection permitted.
What to do next
Almost all of this you can gather yourself in an afternoon with a tape measure and a look at the roof.
Write these down before you ask anyone
- What you want the water for, in order of importance
- The roof material, its rough area and its condition
- What overhangs or sits above the roof: trees, a chimney, a neighbouring building
- Which downpipes you could collect from, and where they are
- The space for a tank, the ground under it and where the overflow would go
- Roughly when your rain falls and how long your dry months run
- What your municipality says about using rainwater indoors
For garden and toilet use, a tank, a gutter screen and a first-flush diverter is genuinely the whole project and any competent plumber can do it. Come to us when you are thinking about indoor or drinking use, because that is where the choices get specific to your roof and your tank. Tell us what you have and what you want it for; we will tell you what we would want to know before recommending anything.
Ask us what the water would needRead further
- Backup water
Includes what rainwater actually needs before anybody drinks it, and why the endpoint is the same for every alternative source.
- What UV does
The disinfection step people reach for first, with an honest account of what it needs to work and what it cannot fix.
- Spun-bonded, string-wound and pleated cartridges compared
If you are filtering tank water, this is what the different cartridges are actually for.
- Micron ratings
Why the micron number on a filter box promises less than most people assume.
Borehole and wellpoint water
Whether you can get water and whether you can use it are two different questions, and the second one is answered by a laboratory, not by the driller and not by the taste.
A wellpoint is a shallow pipe driven into a sandy water table, usually a few metres down and usually only good for a garden. A borehole is a drilled and cased hole that can be much deeper and can supply a house. Groundwater is genuinely independent of the municipal supply, which is exactly why people want it, and its quality is invisible and entirely local. Two houses in the same street can have quite different water. Nothing about the depth, the yield or how clean it looks tells you what is dissolved in it, and the things that matter most for health are all things you cannot taste.
Establish this first
Whether the hole already exists or you are still thinking about it, these four come before any conversation about treatment.
What you are allowed to do where you are
National water law allows reasonable domestic use and stock watering from a source on your own land without a licence, but that is not the whole picture. Municipalities add their own rules about drilling, notifying, registering, metering and whether groundwater may be connected to household plumbing at all, and those differ by municipality. Ask yours before the rig arrives, not after.
Whether there is water, and how much, through the year
A borehole's yield is a property of the ground, not of the equipment, and it moves with the seasons and with what the neighbours are drawing. A hole tested once after drilling in a wet month can disappoint in September. If you already have one, what it did last dry season is the most useful number you own.
What is actually in it
This is the one that cannot be skipped or guessed. A laboratory analysis is the basis of every sensible conversation about treatment, and without it any recommendation is somebody's standard package rather than an answer to your water. Tell the laboratory it is untreated groundwater, say what you intend to use it for and who will drink it, and let them tell you which package and how to take the sample.
What is upslope and nearby
Groundwater picks up what is around it. A septic tank or French drain, a filling station, an old dump, a cemetery, intensive agriculture or a leaking sewer uphill of your borehole all matter to what you will find in it, and they matter to how often you should test. Note what is within a few hundred metres and which way the ground falls.
What is worth discussing
Which of these you need is decided by your analysis and your intended use. Nobody needs all of them, and a supplier who proposes the same set for every borehole has not read yours.
Nothing, for the garden
Irrigation only, on water that is not obviously aggressive
A very common and perfectly good outcome. Plenty of borehole water is used untreated on gardens and lawns for years without trouble, and if that is all you want it for, the analysis mostly tells you whether the salt content and the sodium will harm your soil and your plants over time.
What it does not do
Untreated is a decision about use, not a verdict on the water. Do not let a garden line become a drinking line later without going back to the analysis, and keep it marked and separate from the household plumbing in the meantime.
Iron and manganese removal
Orange or black staining, and water that clouds after standing
The most common borehole complaint in South Africa by a distance. Iron and manganese are dissolved and invisible while the water is underground, then turn to a rust-coloured or black solid on contact with air, which is why the water comes out clear and stains the basin an hour later. The usual answer oxidises them deliberately and filters out the solid.
What it does not do
It is a staining and taste problem, not a safety one, and solving it says nothing about anything else in the water. The right media and the right conditions depend on the concentrations and the pH on your analysis, and these filters backwash, which needs a drain and a flow the installation can actually deliver.
Softening, for hardness
Scale on elements and fittings, poor lather, spotting
Groundwater is often hard, because it has been in contact with rock. If your analysis shows high hardness and you are supplying the house, a softener protects the geyser and the appliances and makes washing behave normally.
What it does not do
It exchanges hardness for sodium and does nothing else — not iron at any real concentration, not nitrate, not bacteria. It needs salt, a drain and a regeneration cycle. On irrigation water it is usually the wrong move, because the sodium it adds is bad for soil structure.
A disinfection barrier, for drinking
Any groundwater anyone in the house will drink
Groundwater is not sterile, and a borehole can be affected by a septic tank, a sewer or surface water finding its way down a poorly sealed casing. If people are going to drink it, the design finishes with a barrier against micro-organisms, placed last so that everything upstream has already taken out what would shield them from it.
What it does not do
A barrier deals with organisms and does nothing at all about dissolved chemistry — nitrate, fluoride, salts and metals pass straight through most of them. It also has to be maintained and it has to be fed water clean enough for it to work. And it does not remove the need for the analysis; it is the answer to one part of what the analysis tells you.
What to do next
If you have a borehole already, the analysis is the next step and everything else waits for it. If you are considering one, the first two items decide whether to proceed at all.
Write these down before you ask anyone
- Your address or the property's location, and whether the source exists yet
- For an existing source: the depth, when it was drilled, and any driller's report you were given
- What it yields, and what it did at the end of the last dry season
- Any laboratory results you already have, however old, with their dates
- What you want the water for, and whether anyone would drink it
- What sits within a few hundred metres and which way the ground falls
- Photographs of any staining, and of the wellhead and its surroundings
Book the analysis with an accredited laboratory first — DWT does not test water, and their sampling instructions govern. Once you have the result, send it to the branch with what you want the water for and we will tell you what it points to and what it does not. If you have not tested yet, ask anyway: we can tell you what to ask the laboratory for, which is a useful conversation on its own.
Send us the analysis and askRead further
- Catalytic media for iron and manganese removal
The staining problem most boreholes have, and how it is actually solved.
- Water hardness
Hardness is the other thing groundwater almost always brings with it.
- Backup water
Puts a borehole in context against the other backup sources, including what testing and treatment it needs.
- How reverse osmosis works
Worth reading before anyone sells you reverse osmosis, so you know what it is for and what it costs you in water.
Looking after what you have
Almost every household water complaint we hear is about equipment that worked when it was installed. Filters get forgotten, tanks are never opened and pumps run until they stop. None of this takes much time; it just has to actually happen.
Have this to hand
- The make and model of every filter, pump, tank and lamp, photographed
- The manual, or a photograph of the label if the manual is gone
- The cartridge or lamp reference, so you order the same thing again
- The date of the last change, written on the housing in marker
- Who installed it and how to reach them
- Any laboratory result, with its date
What a change usually means
- The flow has dropped off
- Usually a blocked cartridge, and the most common of all household water complaints. Check the filter before you suspect the pump or the municipality.
- The taste or smell has come back
- Carbon is exhausted. It is invisible: a spent cartridge flows perfectly and removes nothing, so the returning taste is the indicator that it is finished.
- Staining has started or got worse
- On a borehole, usually iron or manganese breaking through a filter that needs attention. On municipal water, often something in your own plumbing or geyser.
- The pump switches on and off rapidly
- Stop using it and call the installer. Short-cycling destroys a pump quickly and usually means a pressure vessel or a setting problem, not a worn pump.
- The water has gone cloudy or has bits in it
- After an interruption this is usually disturbed sediment from the main and it clears. If it persists, or if it appears with no interruption, it needs looking at.
- A UV lamp has been in longer than a year
- A UV lamp keeps glowing long after its output has fallen below what disinfects. It is replaced on the maker's stated life, not on whether it still lights up.
What to send us
- What you notice, and when it started
- Photographs of the equipment, its labels and the problem
- What your source is: municipal, tank, rain or borehole
- When anything was last changed or serviced
- Whether it affects one tap or the whole house
- Any laboratory result you have, with its date
Service intervals, cleaning methods and replacement parts come from the manufacturer's instructions for your actual equipment. What is here helps you notice a change and describe it accurately; it does not replace that documentation, and it is not a substitute for the installer where the work needs one.
Things people hear that are not true
The ones we correct most often.
If it looks clear and tastes fine, it is safe to drink.
This is the single most expensive misunderstanding about water. The organisms that make people ill are microscopic and the chemicals that matter for long-term health are dissolved and tasteless. Clear, cold, pleasant water can be unsafe, and cloudy water can be harmless. Appearance tells you about appearance.
A filter makes any water drinkable.
Every filter is built for particular things and is silent about the rest. A carbon cartridge that fixes chlorine taste does nothing about nitrate; a sediment filter that clears grit does nothing about bacteria. Matching the treatment to what is actually in the water is the whole job, and it starts with knowing what is in the water.
Borehole water is natural, so it is better than municipal water.
Natural is not a quality grade. Groundwater carries whatever the rock and the surroundings put into it, which in parts of South Africa includes nitrate, fluoride or salts at levels that matter, and it can be affected by a septic tank or a sewer nearby. It also has nobody testing it but you. It can be excellent; you only know by measuring.
A tank means I have water in an outage, so I am sorted.
For availability, yes, and that is a real win. But water does not keep indefinitely: the chlorine fades, warmth and light let things grow, and a tank that fills and stands until the next outage is the hardest case to keep clean. The tank has to be part of the system you look after, not a bucket you forget about.
Rainwater is the cleanest water there is.
The rain is clean. The roof is not. By the time water reaches the tank it has washed a surface that birds sit on and dust settles on, and South African tank studies keep finding faecal indicator bacteria in a large share of samples. It is excellent for the garden and takes real work to make drinkable.
Boiling deals with everything.
Boiling is a good answer to organisms and the right response to a boil-water notice. It does nothing about nitrate, fluoride, metals or salts — in fact it concentrates them slightly as the water evaporates. It is an emergency measure for a microbiological problem, not a treatment for a chemical one.
The questions we get asked
Short answers. Every one ends in a next step.
Do I actually need to test my municipal water?
Usually not. Your supplier tests the water they deliver far more often than you ever would, and for an ordinary taste or smell complaint a test is rarely the proportionate first step. Testing earns its place when something changed and nobody can explain it, when there is a health worry rather than a comfort one, or when someone in the house is unusually vulnerable. Ask your municipality for their water quality report first; many publish one and it is free.
How much does a laboratory test cost, and who do I use?
Prices vary by laboratory and by how much you ask for, so get a quote from two. Use an accredited laboratory, tell them what the water is and what you want to use it for, and let them decide the package — a basic domestic panel is a very different thing from a full analysis and you should not be paying for the second when the first answers your question. Follow their sampling instructions exactly, because their bottles and their holding times govern. DWT does not test water and does not have a laboratory to refer you to.
Should I filter the whole house or just the kitchen tap?
Start from the use. Drinking and cooking is a tiny fraction of what a house uses, so treating only that tap to a high standard is usually far cheaper than treating everything. Whole-house treatment earns its place when the problem affects the house rather than the glass — scale on the geyser element, staining on the laundry, grit in every tap. Plenty of homes sensibly do both, with a modest whole-house filter and a better one at the kitchen.
Can I connect my tank or borehole to the house plumbing myself?
This is the part to get a registered plumber for, and to check with your municipality before starting. The concern is not your comfort but the municipal main: stored or alternative water must not be able to flow back into it, and what device is required to prevent that is set locally, as is whether the connection is permitted at all. Treating the water does not by itself make the connection allowed. Getting this wrong affects your neighbours and carries a real penalty.
How often should I change a filter cartridge?
On what the cartridge's own data sheet says, not on a rule of thumb from the internet. A sediment cartridge is changed when the pressure drop across it says so, which is why a gauge either side is worth having. Carbon is different: it is exhausted invisibly, so it goes on the volume it is rated for, and the returning taste means you left it too long. Write the date on the housing in marker when you fit one, because nobody remembers.
Does DWT install systems or come and look at my house?
No. DWT is a technical supplier to the trade: we sell equipment, and we answer questions about it. We do not install, we do not test water and we do not have an installer referral list. For household filters, our retail side is The Water Filter Factory. For plumbing and pumps, use a competent local installer. What we are genuinely useful for is the equipment question in the middle — what a thing does, whether it suits what you have described, and what to ask for.
Talk to a person
Phone or WhatsApp the branch nearest you. You do not need a water analysis to ask a question. Tell us what you have noticed, what the water is for, and what you are trying to decide, and we will tell you what we would want to know next. We answer equipment questions; we do not install, and we do not test water ourselves.
Cape Town
5 Firgrove Way, Firgrove Industrial Estate, Macassar, 7134
Mon to Thu 08:30 to 16:30, Fri 08:30 to 16:00
sales@definitivewater.co.zaJohannesburg
Unit 067, Inospace Allandale Exchange, 917 Morkels Close, Halfway House, Midrand, 1685
Mon to Thu 08:30 to 16:30, Fri 08:30 to 16:00
salesjhb@definitivewater.co.zaGuides, episodes and calculators
The longer versions, in plain language. Every one of these is written for someone who wants to understand the thing rather than buy it.
- When the tap cannot be trusted
- Backup water: tanks, boreholes and rain
- Water hardness explained
- GAC versus carbon block
- Cartridge types compared
- When to replace a cartridge
- Micron ratings: nominal versus absolute
- What UV does and does not do
- How reverse osmosis works
- Catalytic media for iron and manganese
- Free versus total chlorine
- Choosing a filter housing
Treatment train designersoon
Type in your certificate and get a suggested treatment train. Opening soon, as a calculator, not a guarantee.
/designThis page is general information for South African households, not advice for your particular house, your supply or your health. It cannot tell you whether your water is safe to drink; only a laboratory result for your water can begin to do that, and an official advisory from your supplier overrides anything written here. Where the work involves plumbing, a borehole, an electrical connection or a joint to the municipal main, use a registered person and confirm what your municipality requires before you start.
These guides are general information, compiled from published standards, manufacturer data and our own experience, and we keep them as accurate as we can. They are not a design, a specification or advice for a particular site. Whoever specifies, installs or operates a system, whether an engineer, an installer, a farmer or a plant manager, remains responsible for checking that what is written here applies to their water and their installation, and for the work itself. Definitive Water Technologies accepts no liability for errors in these pages or for work done on the strength of them. When in doubt, send us the analysis and talk to the branch.