In this article, we’ll examine the differences between filtering Rainwater and filtering or city chlorinated water.
My preference has always been rainwater because no chlorine and chemicals have been added to it. However, rainwater still requires treatment, depending on how you're storing your water and what's going on at your home.
Rainwater lands on the roof, goes into the gutter, and into your tank.
The biggest challenge presented by rainwater during that process is sediment. Sediment is silt, clay, soil and grains of sand into your water supply. Sediment is a challenge for all water tanks, regardless of what material they are made from.
A rainwater filtration system is necessary to take your rainwater that last step to being purified enough to drink. A good rainwater sediment filter (prefilter) will take the lumps and bumps out of the water.
If you have Whole Home Filtration, perhaps a rainwater tank filter, you don't need an extra under sink or benchtop water filter.
Stages Of Filtration Required For Rainwater
Rainwater typically goes through 3 stages of filtration before it can be consumed.PreFilter Filter pH neutralisation
The PreFilter takes care of the dirt and sediment.
The second stage filter is to stop the bugs and any heavy metals from the roof.
The third stage is to raise the pH level of the water because rainwater is acidic.
If acidic water runs through your pipes and into the home, you will most likely see it eating out the copper pipework so you can get a lot of limescale or copper coming into your home too.
A filter is a must! You need one at the tank or at your sink - at the very least.
Water Filters For Rainwater Tanks
The Ultrapure cartridges (or Coldstream cartridges) are fantastic for rainwater because they remove heavy metals, herbicides and pesticides and block the bugs because they're ceramic cartridge.
Ceramic is the best for bugs!
If you’ve got a concrete water tank, the lime tends to leach out of the concrete walls and mix with the water, elevating the acidic rainwater up to a neutral pH of around 7. When water is neutral, it doesn’t eat into the copper pipe in the home or attacking the home appliances.
It’s also good for you, too. The human body does not like being in an acidic state because that’s where dis-ease begins.
We always want people to be drinking water higher than 7, so if you've got a concrete tank, you could simply have a sediment prefilter and an ultrapure water filter (Twin Under Sink or Benchtop Water Filter system).
Lime Coming Out Of The Concrete Walls Will Elevate The pH Of Your Water
Any other form of water tank (that isn’t concrete) will not leech lime out of the walls and into the water, so the rainwater will remain acidic.
This is where your third cartridge comes in - a pH neutraliser cartridge.
We're neutralising the water, elevating the pH up to seven, so that people are drinking neutral water.
There is minimal contamination with rainwater, so it’s a great way to go if you can make it happen.
Click here to see our collection of water filters for rainwater tanks.
Filtering Town And City Water
Now, water in the matrix!
Government water starts out as rainwater, of course, but many people live in our cities nowadays, and it's a big challenge for the government and local shires to keep the water supply to everybody's home. A growing population makes it harder every day, so the water being delivered to your home by the government is of a reasonable quality. Still, there’s a lot of chemical in it.
They throw all that chemical in the water so that they can deliver that water to your home, and it doesn’t eat out the water pipe systems on the way. When you go to your tap to get a glass of water, you’ll be getting water at about 7.2 to 7.5.
It does alter, but generally, all across Australia, that's what we find.
They're not going to pump acidic water through their pipes; that would be crazy! So you're always generally going to have alkaline water or pH-neutral water coming to your home, and that’s okay to drink.
The problem is the chemicals and extras added to the water, and the lurking bacteria hidden in the pipelines that deliver the water to your home. So when you go and get a glass of water out of the tap in the capital city, that water has journeyed a long way.
Your water could be coming through pipes from 20, 30, 40, 50 miles away and some of that infrastructure, unfortunately, could be pretty old.
Solution: Point of Use Filter
It’s always good to have either a Benchtop Gravity, Benchtop or Under Sink Water Filter.. An Ultrapure system is a popular example and would do an excellent job for you. The water is filtered through a twin or triple system and comes out of the tap, into your glass, and you know it’s clean!
The other option, which is going to create the best water you can, is Reverse Osmosis.
Reverse Osmosis differs from traditional water filtration, where impurities are stored within the cartridge. Once the water is pushed through a series of filters, the clean water goes into a holding tank, and the contaminants are flushed down the drain.
Stages Of Filtration For Reverse Osmosis
Stage 1: Sediment Cartridge.
The water comes from the tap, enters the sediment cartridge, which removes sediment and other matters like dirt and silt. This improves the taste and appearance of the water. This initial process is essential to protect the carbon filter in the second stage.
Stage 2: Carbon Cartridge.
The second stage is to eliminate chlorine and chlorine compounds. It also removes other particles in the sediment filter like VOCs. The carbon filter is also effective at removing odours. The carbon stage conditions the water before the reverse osmosis starts and helps protect the RO membrane against corrosion by removing chloride.
Stage 3: Reverse Osmosis Membrane.
It is the RO membrane that is the heart & soul of any RO system. The RO membrane splits the water into clean water and wastewater, sending the contaminants to waste and the clean water to your tap.
This is where the Reverse Osmosis membrane filters out organic and inorganic compounds such as fluoride and heavy metals. This stage will also completely strip the water from Total Dissolved Solids (TDS) like sodium, calcium, magnesium will be reduced.
Stage 4: Carbon Post Filtration.
The final stage in the RO process is usually a carbon post-filtration phase that will remove any remaining aesthetic taste or odours, a “polishing stage”, for lack of a better word.
After Reverse Osmosis
Once the water has undergone Reverse Osmosis, we are left with ACIDIC WATER.
The pH after RO is about 6 pH. You don’t want to be drinking it yet!
We want water to be at 7 pH before drinking because water below 7pH carries the risk of stripping the mineral out of your body to keep your body at a healthy pH level.
So what we need then is either an Alkaliser or Neutraliser to bring the water back up to neutral or an alkaline pH (7 and above).
We hope that gives you a better understanding of the differences between filtering Rainwater and Town or City Water.
If you’d like to learn more about Reverse Osmosis, click here to see our in depth Reverse Osmosis guide.
If you have any questions, please feel free to contact us.