What Is The CHEAPEST Way To Filter Water? 5 Scenarios

Water filters are very commonplace, for swimming pools, drinking water or even industrial facilities. The two main variables that drive what type of filtration to use are what sort of water you want to filter and what sort of water quality you are trying to achieve. Growing up on a farm I was exposed to various types of filtration, rainwater to drinking water, murky dam water to garden water and then muddy sludge to a pumpable liquid. These applications all had vastly different filtration systems, with a huge price differential, which got me thinking in simple terms what is the cheapest way to filter water? This was the inspiration behind looking into common types of water and how to improve their quality in the most economical way possible.

The cheapest way to filter water depends on the source and target quality. Sand filtration is probably the cheapest way to filter water, but, it doesn’t guarantee any level of hygiene. Whilst UV filters are the cheapest way to sterilize water but are ineffective against metals and chemicals. It is all relative!

If you straight up want to purify your water for free and aren’t too concerned with specifics or efficiencies, I wrote an article exactly on this topic here: How To Purify Water For Free! 2 Clever Techniques – Lets do water.

Tap Water

Target Cleanliness: Better quality & taste

As a general rule, tap water is good to go for all purposes except for maybe long-term use in agriculture. However, for the purpose of this article, we focus on improving the taste & quality of tap water which can often have a strong taste of chlorine and be full of many trace elements. Without a doubt, the cheapest option to improve tap water is a simple filter jug fitted with some sort of activated carbon system.

Things the jugs can REDUCE:

  • Heavy metals (eg. lead)
  • Chlorine
  • Asbestos fibres
  • Benzene
  • Tiny particulates and other contaminants

Things the jugs won’t help with:

  • Nitrates
  • Dissolved minerals
  • Microorganisms

These filter jugs are extremely affordable and make sense to use, often available online for well under $30!

Bore Water

Wells and groundwater are important water sources for many populations.

Bore Water (aka well water) is generally used for either drinking, cleaning or agriculture. As it is ok for agriculture as is, we will focus on filtering bore water for washing and also drinking water.

Target Cleanliness: Washing cars & Showering

If the main concern is to get groundwater up to an acceptable standard to wash cars, windows etc and shower, the requirements are less strict as microorganisms pose less of a problem. A simple water softener will help remove calcium, magnesium and even iron often associated with groundwater. These hard minerals will form scale and residual buildups on surfaces after the water evaporates, which is annoying when showering (gives your hair that knotty feeling) and washing windows, and leaves cloudy residue rather than a nice clear finish. Water softeners are extremely affordable with good quality options for the entire house available for $200-$250 USD and cheap localized solutions for less than $40! the localized option is perfect for satellite water sources that just have a single tap for instance.

Target Cleanliness: Drinking Water

Unfortunately, water softeners do not remove bacteria from water so another option is required. In terms of price alone, getting bore water up to drinking standard depends on the source, however, for a general answer we will assume there is a normal level of risk of bacteria that will need to be removed. Most water filters you see in households in fact do not remove bacteria at all, they are purely designed to improve the taste. The cheapest option to ensure no bacteria are present in bore water and that it is safe to consume is with a household UV treatment system, reverse osmosis systems will remove most bacteria but not all and shouldn’t be relied on for this purpose. UV systems are available for under $300 and they are capable of servicing the whole house or less than $30 for a single tap/faucet.

Household Wastewater (Grey Water)

Unfortunately, most greywater is not recycled and is released into nature with minimal treatment

Target Cleanliness: Watering gardens

A less common water source to be treated is household water aka grey water (Not including toilet/black water) for use in gardens. Although not common in areas where water is abundant, it is increasingly being adopted in new homes in dry climates like Australia, to make larger gardens a more feasible option. The process generally involves collecting water from showers, hand basins etc, running it through a filter and storing it in a garden water tank for use as required. The primary goal of the filter in this instance is to remove oils, food particles, soaps and other chemicals from the water that could potentially harm plants. As with swimming pools, sand filters are an extremely economic and user-friendly choice which are frequently used, they are available for under $200 or can be made yourself with a garden bed, some gravel and some sand. and can easily remove most visible debris, however, they are not useful if large amounts of cooking oils and chemicals are present. When looking at removing oils & soaps, the filtration process gets more complex, so, if possible collect wastewater from the kitchen sink separately or add in a charcoal filter. Larger-scale charcoal filters (activated carbon) are useful for removing most oils and some chemicals from greywater, the problem is that they require much more upkeep than a simple sand filter and they are also more expensive and less common off the shelf. The best advice is to minimize oils down the drain and use eco-friendly soaps, this will make it much easier to utilize your greywater.


Target Cleanliness: Drinking Water

Rainwater is mostly ok to drink as-is, depending on its journey to your cup! I wrote an article on this specific topic Should Rain Water Be Filtered Before Drinking? 4 Key Points, although to ensure it’s good for drinking, there are some cheap options you can utilize. Generally speaking the main concern with rainwater is bacterial buildup when it is in storage for too long, the most efficient and economic option to remove any potential bacteria from rainwater is a UV system. UV systems are available for under $300 and can serve the whole house for less than $30 for a single tap/faucet.

Swimming Pools

Target Cleanliness: Clear swimming water

Filtering swimming pool water is necessary as sand and other debris build up over time, they need to be removed! Not to be confused with chlorination which targets microorganisms, swimming pool filters recirculate water from the pool through the filter and back to the pool removing non-living contaminants. Sand filters are the most affordable option for filtering swimming pool water, particularly due to their extremely low operating cost. Generally speaking, sand filters will last for many years and even decades if properly maintained. Routine maintenance is simple, water is pumped through the pump in a reverse direction flushing the contaminants from the sand and enabling its continued use.

Things it will remove:

  • Dirt, stones, sticks etc
  • Small precipitated carbonates and other inorganic substances.

Things it won’t remove:

  • Anything dissolved in solution like salts, chlorine, bacteria etc.

Sand filters are available for under $200 and are almost exclusively used in conjunction with an ozone or chlorine treatment system to deal with bacteria, pathogens and other microorganisms.


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