Basic water quality testing

When buying a property is easy to fall into the trap of assuming that any water is good water. Unfortunately we learnt this the hard way. When we bought our property at Nanango, we thought the dam looked good and we would have plenty of water for the cattle, chooks and garden. The day we moved in with all our animals, our neighbour dropped by to tell us that our dam was saline. According to our neighbour, the previous owner had nearly ended up with two dead horses as they had refused to drink from the dam.

We promptly tested the water with an electrical conductivity (EC) meter that we already owned from back when we grew hydroponic tomatoes (pre-blog days) and found that the water was indeed saline. It was OK for the cattle water, but no good for the chooks or garden. The most annoying thing was that we already owned the EC meter and hadn't thought to use it to test the water because we had no idea that dam water could be salty. Since then we have used it on several properties that we were considering buying. Even if you still go ahead and buy the property, at least you know what you're getting.

my helpful lab assistance

The other basic test for water quality that can be useful is pH. I bought the pH meter to use for soil pH, but when I was struggling to calibrate it using our tank water, I realised that the rainwater in our new plastic tanks was actually very low pH due to our proximity to a power station which effectively generates acid rain. We have had to add limestone to the water to increase the pH, which I explained back here.

Our EC meter and pH meter have proved to be very useful in testing water. We regularly test water from our dams, bores and tanks and for other people. You can buy a conductivity meter for around $200, and a pH meter for less than $100. These two meters can tell you an awful lot about your water quality, preferably before you make the mistake of buying a property with poor water quality! If you need to know exactly what is in your water, you can also send a water sample to a laboratory for around $50-200 depending on the tests that you request, they will also be able to advise suitable applications for the water. Other tests can be used to further assess water quality - summaryof water testing.

a pH meter (that's our rainwater!)

a conductivity meter (again, on rainwater)

Ideally good quality water will have low salinity (less than 500 ppm) and pH around 7. Typically rainwater can end up with a pH well below 7, and this can cause corrosion in metal plumbing fittings, as I discussed previously. If pH is higher, you may find that you have dissolved calcium and magnesium, known as “hard water”, which causes soap to form a scum rather than suds (more on soap chemistry and how soap works). For household water, its possible to use a water softener to remove these minerals, but this is impractical for larger applications (stock water or irrigation) (see options for softening water and maintaining a cation exchange resin water softener). As salinity increases, the water becomes unsuitable for irrigation (and this link) and for stock water. It is usually restrictively expensive to remove minerals from water on a large scale, so its best to test your water sources before buying a property, so that you know the water quality and its suitability for various applications.