In this article, we will cover everything you need to know when it comes to rainwater.

We will also show you how to test the pH of rain water, the risks associated with consuming water from a rainwater tank. 

Immature Water.

In Australia, we have rainwater that lands on the roofs of sheds, travels down the gutters, through the pipes and into the water tank.

This water, controlled by the sun, is evaporated up off the ocean or the land, hits the clouds, creates rain, then drops on top of the roof. This is called immature water.

Mature Water.

Mature water is rainwater at the end of its cycle. It has landed on the ground at an acid pH of about 6.

The water soaks into the earth and picks up minerals. Water molecules remember everything they ever come in contact with, in their existence.

Rain on Ground

Once it filters through the ground, it'll eventually resurface and end up coming out of a spring. That's what we should be consuming - beautiful spring water! Clean, healthy, full of minerals and with the right pH level.

With rainwater tank water, we have trapped the water prematurely.

It hasn't gone through the earth, so it's not ready for us to drink yet.

In this case, the government hasn't got their hands on it, so it’s not full of chlorine and fluoride. And it’s not contaminated by urban living and city corporations.

So we trap it on the roof and funnel it into a tank.

The rainwater tank we have in the video holds water at about 5.5 pH, which is too acidic for people to drink regularly.

What’s Wrong With Rain Water?

It's Acidic.

The pH of rain water is usually somewhere between 5 and 6.5 pH, at the absolute best.

If you store your water in a concrete tank, the lime will leech out of the walls of the concrete tank and elevate the pH of the water.

If you do a pH test, the rainwater pH level will probably be 7, so it’s getting back to neutral. The lime leaching out of the concrete will make the water neutral.

As human beings, we need to be consuming water at a pH level of 7, so it makes sense that the water flowing through the home should be at a pH of 7.

If you see green/blue staining on your basin, that means acidic water is going through a copper pipe, and it's eating the soluble copper away, and that's what the green colour on your basin is.

pH Of Acid Rainwater.

The pH of normal rainwater is typically 5.5 to 6.

If you’re using a concrete tank, the rainwater pH value is likely 7, so you pass this test.

Rain Water pH Level Indicator

If it's held in an aqua plate (which is steel outside, plastic inside), in fibreglass, poly or big steel liner tanks, none of these have got anything to alter the state of the water or add a mineral to elevate the pH so the water will remain acidic.

What Happens If You Continuously Consume Acidic Water?

When you consume acidic water, the water can take up to three weeks to go through your body. While the water is travelling through your body, your body works very hard to bring it back to a pH of 7. This process can strip your body of precious minerals and leave you feeling less than optimal for weeks/months, or even years.

Other Risks Include:

Exposes You To Excess Contaminants That Are On Your Roof Or Gutter.

Metals and minerals present in acidic water can include iron, copper, manganese, and zinc. This is due to them being dissolved in your water as result of touching copper pipes, your roof or gutters. 

Exposure to too much of these metals may lead to illness and poisoning. Acidic water can also have a metallic and unsavoury taste, which isn’t exactly what you want from the water you drink.

Damages Your Teeth.

Acidic water can accelerate the corrosion of your teeth and damage the gums.

Places Young Children At Risk.

Elevated levels of metal contaminants found in acidic water can cause plenty of health issues that could prove fatal or debilitating for children. Vomiting, diarrhea, kidney disease, liver disease, stomach cramps, and nausea are among the leading health issues caused by the consumption of acidic water.

Damages Your Water System And Pipework.

Due to the high acidic level in the water, plumbing can get damaged and corroded. It can even dissolve the copper right off the pipes.

Calcium Malabsorption.

When consuming acidic water, your body has a reduced capacity to absorb calcium. Calcium is important for the ongoing nourishment of your bones.


Gastrointestinal Distress.

The leaching of metals from acidic water often leads to a gastrointestinal upset. Whenever you are overexposed to zinc residue from pipes, you can get nausea, diarrhea, and vomiting. You can also get these symptoms upon overexposure to copper.


Increased Exposure To Contaminants.

When large water bodies have a pH level that is too high or too low, contaminants can increase. This increase in contaminants can lead to disease-causing bacteria, parasites, and elevated ammonia levels.

Prolonged consumption of acidic water can lead to common health issues, including gout or arthritis, to name a few.

How To Add Mineral And Raise pH of Rain Water.

The best course of action to treat acidic water is to use a Whole House Rain Water Tank Filter System Complete with Ultraviolet Light & Positive Charged Water Magnet, and a Whole House pH Elevation System.

A Rain Water Filter will treat bugs, bacteria and other microscopic organisms, but it won’t solve acidic water.

There are two different types of water filters; gravity-fed and pump-fed. So be sure to talk to us about what your setup is.

A pH Elevation System will solve the problem of acidic water by adding mineral to the water and elevating the pH.

If you’ve got a concrete tank, you will not need a pH elevation vessel, but we highly recommend at least a Twin Rain Water Filter to take care of the bugs and bacteria.

Suppose you have steel, plastic, colorbond or anything other than concrete. The water will not interact with the tank and will remain acidic. In this case, we recommend a pH elevation system.

Once the water is in the house, we recommend an under sink water filter at the very least to remove the bugs, in the off chance your UV light stops working due to electrical short, blown bulb other power issue. 

Click here to see our full collection of Rain Water Tank Whole House Water Filters.


Before you decide what your complete home setup should be, you need to test the water in your tank.

To find out the pH level of your Rain Water, you can use a pH Test Kit.

Simply run 15 millilitres into the pH tester, and consult the colour chart to get a reading.

You’re looking for a pH minimum of 7 to be able to drink it.



Once there is mineral added to the water, it’s good to drink, your appliances will last longer, and the pipework in your home will love you for it.

If you have purchased any of the products mentioned in this article and require any further assistance with the installation, please contact us.

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