Some more detail on what we do that I wrote a while back. I forgot I saved it.
It is worth noting that chlorine treatment is the chosen treatment for 99% of town water supplies.
Prices are AUD$.
9/11/2021
- Water sources
We will fill with water from creeks, dams, rivers, cattle troughs bores or artesian sources.
Most water can be made to be biologically safe. Chemical contamination is more difficult, so avoid suspect sources not used by humans or animals.
Also avoid water that is cloudy as it contains larger quantities of colloidal clay which will be removed by fine filters, but will also block them quickly. If you cannot avoid cloudy water, it can be batch treated by the bucket full by adding a tiny amount of alum, which will cause the clay to coagulate and sink to the bottom.
- Pump.
We use a standard RV style pump to fill our tanks from ground sources. They will self-prime and lift from a couple of metres from the water source to the tanks. We use a “spare” pump for this job, but with an in-line tap and a bit more plumbing, it is possible to use the existing pump in the RV.
- Chlorination.
We chlorinate ALL water in our tanks, every time we put any water into any tank. For this we use liquid swimming pool chlorine (sodium hypochlorite) that is 12% free chlorine. We add it at a
minimum rate of 5ml per 100L of water, more if the water is suspect. We would typically add 10ml/100L of water. Some extra never hurts.
Cheap household bleach can also be used. Get some without additives, which is sometimes difficult. It is typically about 4 or 6% free chlorine (as sodium hypochlorite). Addition rates need to reflect the concentration.
Chlorine in water naturally breaks down quite quickly and disappears, particularly if the water is poor quality and especially if the water gets warm which it does in the tropics. Some believe that ‘bugs’ cannot grow in a tank without light. This is false. The rate of growth can stop in cold conditions, but accelerate rapidly in water of 30C or higher which can be common up north.
It is also important to chlorinate showering water. While not common, Legionnaires Disease bacteria will grow in warm water and if breathed in while showering, it can kill a less than 100% healthy adult.
The chlorine level in the water can be easily measured with swimming pool test strips, but as a general rule, if you cannot smell it in the water that has not been filtered, it is time to add some more.
- Filtration.
We do not filter any water while filling except a very coarse one to keep out some sand, rocks and leaves etc. when pumping from creeks etc.
Between the pump and the taps, we have a 10” twin cartridge household style filter housing. These are available for well under $100.
The first housing is fitted with a 5um or 10um sediment filter. This is simply to take the bulk of the “large” contaminants out of the water. I buy these from a local water treatment company for $2 each. Top price would be $10 each.
The second housing has a 0.5um carbon block filter. These are around $25 to $50 each, depending on source. They can include silver, which is a good idea if the system is not used on a daily basis as it reduces the likelihood of bacteria growing in the filter itself. Any system that has not been used for several days, or more, should be flushed with 10L of chlorinated water prior to consumption.
Carbon block filters will remove many biological and chemical contaminants (including any chlorine remaining in the water).
I buy filters according to specification, not by brand names.
Filter elements should be changed at least annually.
Cheers,
Peter
OKA196 motorhome
