Blue/Green Stain on sinks & tap fittings?

I have green / blue staining on my bath and tap fixtures… what is it?
Answer: This can occur when the water pH is lower than 7 pH.
When the pH in water drops below 7 the water becomes acidic - and depending on how low the pH drops, it may begin dissolving copper from your pipes. The most common symptom of this is green and blue staining on your tap fittings, in your sinks or in your bath and shower recesses.
Most homes have copper pipes - and copper being a soft material is generally always the sacrificial metal when the chemistry of the water isn't quite right.
Although it's rare, we have seen copper leaching from the pipes when the pH is over 7, however this is very complex and not often recorded.
Copper leaching is a very serious issue. Firstly it's a health issue, and secondly it's destroying the integrity of your copper pipes which can lead to tiny pin holes in the pipes that can cost tens of thousands of dollar to correct.
If the above mentioned is happening to you:
If you are reading this or contacting us, the odd are that you have tank or bore water - not municipal (mains) supply. Low pH in water is generally associated with tank or bore water. Municipal supplies are rarely lower than 7 pH due to the chemicals added and the treatment processes the water is subjected to before you receive it.
What causes the water to have a low pH?
Some chemists may have a different view point on this, however based on 20 years of experience we deem the main cause of low pH to be carbon dioxide in the water, and in some cases water that is too pure.
When it rains the water picks up carbon dioxide from the atmosphere which can also be called carbonic acid. This alone isn't the sole cause however, and this is where things get tricky.
If you have a clean roof, first flush diverters, and you regularly clean and sanitize your tank, you are more likely to experience acid water than someone that doesn't pay any attention to maintenance, and never cleans their gutters or tank. Strange you say? What's going on here?
Water is the most volatile substance on the planet, it will wear away anything in its path and form great canyons in the ground. Basically it's likely to dissolve anything in its path if it's hungry, therefore if you give it something to feed on, it will once again settle down.
In more analytical terms, the more pure the water - the lower the pH>>and the more hungry the water is to balance its pH.
When this pure, water loaded with CO2 lands on your roof, it immediately begins dissolving anything in its path in an attempt to once again balance its chemistry (pH). When you have no leaves, first flush diverters, (the whole box and dice to keep your tank water clean), the water has nothing to feed on and remains in an acid condition. So in summary, if you do the right thing and keep your catchment clean, you may actually pay the price by retaining a tank full of acidic water with a pH anywhere from 4.5 - 6.5 pH. We’re not saying don't keep your catchment system clean, we are simply attempting to explain why your water remains in an acidic condition.
How to correct low pH Water:
Now that you understand why you have copper (blue or green staining) you should also now realise that all you need to do to correct this is to feed the monster to settle it down again.
The best way (and in our experience the most successful way) to do this is to place a Calcite Filter inline after the pump and before the house.
How a Calcite Filter works:
This filter contains a large amount of Calcite Marble (calcium). Calcium is one of the pH buffers that control the behaviour of the pH.
When the acid water flows through the calcite marble, it dissolves the quantity of calcium it requires to balance the pH back to 7 or slightly above. This in turn, then stops the water from being aggressive on your copper pipes. In effect you have fed the monster and it is no longer hungry or aggressive.
From this point your copper pipes are safe again and so is your families health.
The filter need to be large enough to offer the water enough contact time with the calcite for it to raise the pH. To size this filter correctly you need to test the pH of the water>>DO NOT SEND A SAMPLE TO US OR TO A LAB FOR pH TESTING.
The reason being is that once a sample of water is removed from the main body of water the chemistry of this sample begins to change, and because the pH is a measure of the chemistry, you will inevitably be given an incorrect reading.
Answer: This can occur when the water pH is lower than 7 pH.
When the pH in water drops below 7 the water becomes acidic - and depending on how low the pH drops, it may begin dissolving copper from your pipes. The most common symptom of this is green and blue staining on your tap fittings, in your sinks or in your bath and shower recesses.
Most homes have copper pipes - and copper being a soft material is generally always the sacrificial metal when the chemistry of the water isn't quite right.
Although it's rare, we have seen copper leaching from the pipes when the pH is over 7, however this is very complex and not often recorded.
Copper leaching is a very serious issue. Firstly it's a health issue, and secondly it's destroying the integrity of your copper pipes which can lead to tiny pin holes in the pipes that can cost tens of thousands of dollar to correct.
If the above mentioned is happening to you:
- read the literature below and then contact us
- run your water for a couple of minutes before taking drinking or cooking water to ensure your have flushed the pipes. Continue to do this until you have the problem corrected.
If you are reading this or contacting us, the odd are that you have tank or bore water - not municipal (mains) supply. Low pH in water is generally associated with tank or bore water. Municipal supplies are rarely lower than 7 pH due to the chemicals added and the treatment processes the water is subjected to before you receive it.
What causes the water to have a low pH?
Some chemists may have a different view point on this, however based on 20 years of experience we deem the main cause of low pH to be carbon dioxide in the water, and in some cases water that is too pure.
When it rains the water picks up carbon dioxide from the atmosphere which can also be called carbonic acid. This alone isn't the sole cause however, and this is where things get tricky.
If you have a clean roof, first flush diverters, and you regularly clean and sanitize your tank, you are more likely to experience acid water than someone that doesn't pay any attention to maintenance, and never cleans their gutters or tank. Strange you say? What's going on here?
Water is the most volatile substance on the planet, it will wear away anything in its path and form great canyons in the ground. Basically it's likely to dissolve anything in its path if it's hungry, therefore if you give it something to feed on, it will once again settle down.
In more analytical terms, the more pure the water - the lower the pH>>and the more hungry the water is to balance its pH.
When this pure, water loaded with CO2 lands on your roof, it immediately begins dissolving anything in its path in an attempt to once again balance its chemistry (pH). When you have no leaves, first flush diverters, (the whole box and dice to keep your tank water clean), the water has nothing to feed on and remains in an acid condition. So in summary, if you do the right thing and keep your catchment clean, you may actually pay the price by retaining a tank full of acidic water with a pH anywhere from 4.5 - 6.5 pH. We’re not saying don't keep your catchment system clean, we are simply attempting to explain why your water remains in an acidic condition.
How to correct low pH Water:
Now that you understand why you have copper (blue or green staining) you should also now realise that all you need to do to correct this is to feed the monster to settle it down again.
The best way (and in our experience the most successful way) to do this is to place a Calcite Filter inline after the pump and before the house.
How a Calcite Filter works:
This filter contains a large amount of Calcite Marble (calcium). Calcium is one of the pH buffers that control the behaviour of the pH.
When the acid water flows through the calcite marble, it dissolves the quantity of calcium it requires to balance the pH back to 7 or slightly above. This in turn, then stops the water from being aggressive on your copper pipes. In effect you have fed the monster and it is no longer hungry or aggressive.
From this point your copper pipes are safe again and so is your families health.
The filter need to be large enough to offer the water enough contact time with the calcite for it to raise the pH. To size this filter correctly you need to test the pH of the water>>DO NOT SEND A SAMPLE TO US OR TO A LAB FOR pH TESTING.
The reason being is that once a sample of water is removed from the main body of water the chemistry of this sample begins to change, and because the pH is a measure of the chemistry, you will inevitably be given an incorrect reading.
Testing your pH:

GT28-107 pH Test Strips
We are not generally a fan of paper test strips but in this instance they are the best option.
If you use a pocket pH test meter in pure water it's likely to read much higher than it actually is, for example you could take a reading of 8.5 pH when in fact the true reading is only 6.5. The reason for this is that rain water is close to pure, so it doesn't have any significant electrical conductivity that pH pocket meters need in order to offer an accurate reading (unless you spend a lot of money on a meter that compensates for this problem).
Titration dropper tests are also not recommended because they use acid reagents that will also effect accuracy on the pH in pure water.
So back to the test strips, be sure they are new (check the use by date before testing) and also use a recognised brand to ensure they will offer the most accurate reading possible. Once you have your test strips, take your test on site >> never rely on laboratory results to be accurate on tank water pH testing.
Once you have an accurate pH reading contact us for further and more specific information on what to do next.
If you use a pocket pH test meter in pure water it's likely to read much higher than it actually is, for example you could take a reading of 8.5 pH when in fact the true reading is only 6.5. The reason for this is that rain water is close to pure, so it doesn't have any significant electrical conductivity that pH pocket meters need in order to offer an accurate reading (unless you spend a lot of money on a meter that compensates for this problem).
Titration dropper tests are also not recommended because they use acid reagents that will also effect accuracy on the pH in pure water.
So back to the test strips, be sure they are new (check the use by date before testing) and also use a recognised brand to ensure they will offer the most accurate reading possible. Once you have your test strips, take your test on site >> never rely on laboratory results to be accurate on tank water pH testing.
Once you have an accurate pH reading contact us for further and more specific information on what to do next.