Is there a need to use green sand filters in your swimming pool?
This question can be quickly addressed with another question. Do you live in a hard or soft water area? If the answer to this question is soft water, then the need for a green sand filter isn’t as paramount as it would be in a hard water area. The reason for this is the chemical composition of the water supply in your area.
Supplies vary according to the types of rock or substrate that the water flows through on route to your property. Sometimes local water treatment plants will use industrial sized green sand filters to remove the harmful metals in the water, before they get anywhere near your house, but this isn’t always the case.
If the mineral content of the water is too strong with suspended metals such as iron, sulphur and hydrogen, it can affect not only the colour of the water, but also the smell and taste. You can now see how this problem can be exacerbated by extra water usage, for instance by filling an outdoor swimming pool.
In this situation a green sand type of filter can improve water quality and purity for drinking purposes and in combination with a general sand filter can clean and maintain swimming pool water, so that you pool has clear, odourless water in which to swim.
Drinking water which has high iron content will often turn a reddish-brown colour and can be very un-appetizing to drink, quite apart from the taste. If you have high sulphur levels then you will also suffer from that rotten egg odour.
In a swimming pool environment, excess sulphur in the water can cause skin irritations, so the removal of all described pollutants has a two-fold benefit.
A green sand filter uses special manganese sand to remove the metals, this sand incorporates glauconite which actually removes manganese as well as the other metals. A naturally occurring sand in the ocean, this filter media is bluish in colour and helps trap the suspended metals within the sand, thereby giving you a chance to remove the waste materials during the cleaning process.
With this in mind are there any negatives to using a green sand type filter?
Only two spring to mind, but these are hardly causes for concern.
The filters can be quite pricey and you can easily spend over $1000 on some models, but others can be purchased for a more modest price.
Like any type of filter, eventually the filter media will become over saturated with the contaminants and the sand will need replacing, but the same rules apply to general sand filters as well.
To extend the usable lifespan of the sand you can apply potassium permanganate to the media, this will improve the efficiency of the sand filtering process and save you money in the long run. This can be particularly effective when filtering large amounts of water on a regular basis – if for example you owned a large outdoor swimming pool.
If you keep the acidity level in the pool at a steady 6 to 8.5pH, this will also create the working environment for the filter to run at optimum levels.
In summary, a green sand filter should really be an essential purchase and accompaniment to the standard filter, especially if you live in a hard water area and maintain a large swimming pool.