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salt - magnified
Image of swimming pool salt under a microscope.

Contaminated salt leads to stained pools

Almost daily we receive telephone calls from distressed clients saying the following – “I got some cheap salt from my local hardware store and now I’ve got these ugly brown stains in my pool”.  Often, this brown staining becomes evident within hours of adding the salt to the water.  Many pool owners around the world face this issue. What are the key differences between bad salt and good salt and why does it matter to your pool? Let’s find out.

Good salt versus bad salt.  What’s the difference?

All salt has the same basic properties. However, the mineral, water and metal content that accompany pool salt can vary significantly from brand to brand.  For this reason, the quality of salt used in your pool has a significant impact on the volume of minerals and metals that are dissolved into your pool water over time. These minerals will later discolour and stain your pool interior, particularly if your pool water chemical balance is not maintained.

We all know that pool water evaporates over time. However, many pool owners are not aware that these minerals, metals and contaminates from salt do not evaporate even once dissolved in the pool. These minerals remain suspended in the water, even when the pool is topped up with fresh water. Using quality salt will significantly slow down this mineral accumulation in your pool.

How can I recognize poor quality salt?

There are 5 things that typically characterize poor quality salt.  They are as follows –

  1. Salt crystal size is large
  2. Salt is discoloured
  3. Salt is slow to dissolve
  4. Salt turns water murky when added
  5. Salt leaves brown stains on your pool floor

If the salt brand you are currently using matches ANY of the attributes in the list above then we strongly suggest trying an alternative.

What does good quality salt look like?

There are five things that characterize good quality salt.  They are as follows –

  1. Salt crystals are fine
  2. Salt crystals are fast dissolving
  3. Salt bag displays a purity level of at least 99.5%
  4. Salt is brilliant white in appearance
  5. Pool water feels soft and comfortable for swimmers

How much extra is good quality salt?

Most pools need around 10-12 bags of salt per year to maintain correct salt levels.  The cost difference between poor and high quality salt is around $4 per 40 lb bag.  This additional cost for quality salt is not significant.  On the other hand, the cost of removing stains caused from poor quality salt can sometimes be over $1000.00. From a financial perspective, cheap salt does not make any sense.

Most pool owners spend less than $120 per year on pool salt.  It is unwise to cut corners by using cheap salt when the consequences can be so costly.

There are times when inexpensive brands sell reasonably high quality batches of salt.  However, less expensive brands need to source lower grade salt in order to meet the low prices some consumers demand.  Therefore, the chances of purchasing a contaminated batch of salt is generally higher with less expensive brands. High purity, fine salt is in demand in several industries and simply costs more to buy.

Another thing to be aware of in terms of cost is that salt is sold by weight.  Some low cost brands will buy moisture rich salt at a lower price in order to undercut their competitors.  Because moisture is not desirable in salt, it is sells for a lower price.  This means that if the salt moisture levels are high then you’re actually paying for water rather than salt! Remember, salt is sold by the total bag weight, not by the actual amount of pure salt in the bag. Therefore, the actual amount of pure salt you have in your salt bag will depend on the quality of the salt, not the total weight of the bag.

Although no brand or batch of salt is 100% pure and completely free of all contaminates, high quality brands generally have better quality control and more accurate measures to monitor mineral content.  When added correctly to your pool, good quality salt saves you money over the life of your pool and will actually cost you less in the long term.

If your pool has salt staining that you cannot remove, please feel free to call The Pool Stain Removers today.  We can help you remove salt stains without draining your pool water.

Do you have any comments or experiences with salt that you would like to share?  We look forward to hearing about them via the email address on our website.

salt stains
Our client in Melbourne, Australia placed a full bag of salt on the steps of their pool and left it to dissolve overnight. The next morning the steps and the entire pool had a horrible brown stain caused from contaminates within the salt.

References

Colour, crystal size and purity – http://www.poolandspareview.com.au

Customers upset and complaining about staining from cheap pool salt – http://forums.whirlpool.net.au/archive/1640290

Adding salt to your pool correctly – http://www.saltwaterpoolandspa.com

Salt quantity needed per year – http://www.poolfab.com.au

Long term benefits of using good quality salt – http://www.riverpoolsandspas.com

Salt graded by water content – http://www.saltcomindia.gov.in