I go on the web, type in water quality, and up comes sites with all sorts of UV systems and prices from just a couple of hundred dollars way up to thousands...confused?

Let's put the options into categories
                        
Town water
Rain Water
Bore Water
River, stream water
Conclusion
 
Town Water
 
This is a simple area to cover as most homes need to run 2 x Carbon filters on the incoming mains water. Protect these cartridges with a 1 micron.

Forget these little under bench kitchen taps that dribble water, I find these hardly every get used because they are so slow defeating the purpose of their intended use.

Chlorine is designed to kill bacteria and also kills yeast, so if you are a keen baker, the carbon filtered water makes a huge difference in bread and cake making, a must for any commercial kitchen.

Filter the whole house so you and take out most of the Chlorine, Fluoride and many other chemicals in your water.

No more smelly chlorine showers, no more scaly residue on the glass in the shower and a massive reduction in chemical intake for you.
 
UV Water Systems Ltd Carbon filters are $27 + GST each, so a yearly replacement is very cost effective.


Rain Water
 
If you have birds on the roof the chances you have E Coli in your water is extremely high. Young children are very susceptible, so be very careful with this.

Kitchen under bench filters aren't what I would call safe as a single whole house clean water supply via large filter housings.

Filter housings are $140+GST each
 
If you only have a small under bench filter tap in the kitchen the water in your shower is untreated, the water in your hand basin when you clean your teeth is untreated, the dishwasher doesn't run at a high enough temperature so untreated water is washing your dishes and leaves a bacteria residue.

If your tank is old and has sludge in the bottom, I suggest you have the water tested as the list of possible bacteria and diseases for me to list here is too long.

Recommendation is – “Do it once and do it right” install a UV Water Systems Ltd water proof UV filtration system with a solid aluminium cover. These start at $1680 + GST and are very easy to install.


Bore water
 
This is a long one so I will just cover the points to look out for and always have your water tested by an independent testing authority – Don't get your local mate who owns a backyard pump company do this as you may end up paying for many things you don't need.

Deep bore normally have dissolved rocks such as Lime, Iron, and other health risk minerals like arsenic and or be acidic which will eat your copper pipe and hot water cylinder.
Deep bores may need to run a water softener before a UV sterilisation filter system to clean up your water as water high in say, Lime, can clog your pipes very quickly and destroy any heating elements. Many companies that manufacture water heater and califonts will not accept any warranty claims for this.
 
Shallow bores can pick up septic tank run off, cattle effluent and can be very high in phosphates etc
 
Check what you have in your water and get it fixed correctly.
 

River, stream water collection

As an example, I will say check out what pollution is in the Waikato River – need I say more!
Industrial , farm, human, aircraft pollution all gets mixed and what you have can be  very toxic – get it checked.
Read the Rain Water paragraph.
 

Conclusion

Always have your water checked via independent authority
Install the correct equipment to do the job, don't go for the cheapest, because we see this every time, it will cost 150% more to do it again, properly!
If you have any bacteria in your water you need a UV Water Systems Ltd sterilisation system.
If you have dissolved rocks in your water, you need to install a water softener.