Using Bore Water in Swimming Pools
Author: Direct Pool Supplies Date Posted:6 September 2018
Source water can have a major impact on all facets of a residential swimming pool. Not only can it affect the water chemistry but it can also be detrimental to equipment, pool surfaces and bathers and their comfort levels. In this section we will cover the following topics:
Why is bore water a problem
Initial treatment of bore water
Ongoing treatment of the pool water
River Water and Dam Water
Initial treatment of River and Dam water
Ongoing treatment of River and Dam water.
Initial treatment of Seawater
Ongoing treatment of Seawater
Why is bore water a problem?
Bore Water contains high levels of Total Alkalinity and/or high levels of Calcium, Silicates, Iron, Manganese, Salt and often has a low pH and a high temperature.
The dissolved metals in particular can be highly detrimental to a pool and if at all possible it is better and cheaper to buy in fresh water.
Salt Chlorinators should not be fitted to bore water pools because the cell clogs up very quickly, within a day so the owner is forever cleaning it.
Initial treatment of the pool:
No two bores produce the same quality water so it is not possible to give a simple formula for the initial treatment.
A common analysis might give a Total Alkalinity of 600PPM and a pH of 6.0. This water would not be very pleasant to swim in as the low pH would cause sore eyes and itchy skin and would use large amounts of Chlorine trying to keep a Free Chlorine of 3.0PPM.
The initial treatment would be to bring the pH up to 7.4 with small amounts of Soda Ash added every two hours.
This tends to precipitate the dissolved metals such as Iron so often the water turns brown and the walls are stained.
If this happens a treatment with Lo-Chlor Multi Stain Remover followed by Lo-Chlor Maxi Floc Plus (2 Kg of Soda Ash followed by the addition of the floc) will drop all the metals out of solution into the floc which is then vacuumed to waste.
Do not attempt to filter a brown pool as the metals will clog the filter.
When the pH is OK Superchlorinate with Chlorine.
Ongoing treatment of the water:
The Total Alkalinity is best left at the high levels and allowed to come down naturally (it will take three months or more).
If Hydrochloric Acid is added the pH quickly drops but the Alkalinity only falls very slowly.
If the pool owner does want to get the Alkalinity down it is best to add small (250MLS) doses of Hydrochloric Acid diluted in a bucket of water every three days.
If the Calcium content of the pool is high scaling will occur very rapidly.
If Calcium levels are high you can treat it effectively with Calcium Hardness Reducer.
Once the level is more acceptable we then recommend maintenance treatment with Scale Eliminator. This should be repeated every 2 months.
Very often after adding chlorine to the pool the water will immediately turn brown. The ongoing use of Ultra-Kleer Plus 4 in 1 will help to prevent this problem. We sell an enormous amount of this product in larger size containers through our pool shop outlets to pool owners living in rural areas etc
River Water and Dam Water
The difference between Bore water and River and Dam Water is the high organic content of River and Dam Water and the fact that they are usually very cloudy. Rivers and Dams also contain trace metals like bore water so they do need to be treated and maintained.
In an ideal world, the pool owner would have a large tank where he could treat the water before adding to the pool. As this is not usually the case the treatment is as follows:
Turn the filter valve to recirculate (the fine sediment would clog the filter very quickly).
Fill the pool up to 75MM above the skimmer.
Turn on the pump.
Add Soda Ash in 2 Kg lots (waiting 2 hours between additions) until the pH is 7.8 to 8.0.
(this pH is necessary to remove dissolved metals).
Add 1L Floc
Turn off the pump and leave overnight.
Vacuum to waste.
Turn filter valve back to filter and turn on the pump.
Adjust pH to 7.2 to 7.6 with Hydrochloric Acid.
Add 20 Litres of liquid Chlorine. Wait two hours and check Free Chlorine and Combined Chlorine.
If combined Chlorine is more than half the free Chlorine add another 20 Litres of Liquid Chlorine and repeat the process.
Finally, balance the pool water.
Whenever the pool is topped up with more River or Dam water you will need to add a strong clarifier or a flocculant if the pool is very cloudy.
For the clarifier, we recommend Ultra Kleer Plus 4 in 1. Along with being a clarifier this unique natural clarifier will also remover unwanted metals, oils and particles from the water.
If a floc is needed we recommend Maxi Floc Plus.
The pool should be Superchlorinated and the combined Chlorine checked to make sure it is below half the free Chlorine.
Seawater is not recommended for normal swimming pools.
It should only be used if the pool is to be filled and emptied on a regular basis.
Seawater quality varies depending on the time of year but often contains types of Algae spores not commonly seen in freshwater pools and also minerals that form stains and/or coloured compounds with Chlorine.
If clear, adjust pH to 7.2 to 7.6 and Superchlorinate with 20 Litres of Liquid Chlorine
After two hours check the combined Chlorine and if above 1.0ppm repeat the Superchlorination.
Repeat until the combined Chlorine is below 1.0ppm.
Adjust Total Alkalinity and Hardness as required.
Treat as if a freshwater pool paying particular attention to cleanliness of the salt chlorinator cell if a salt chlorinated pool.
To prevent calcium build up on the salt chlorinator cell use Scale Eliminator
When cleaning calcium off the salt cell use Clean Cell Plus. Do NOT use hydrochloric acid.
Clean Cell Plus is a unique blend or organic and inorganic acids that is very effective but will not harm the precious metals of the salt chlorinator cell.
It is reusable and will prolong the life of the salt chlorinator cell.
If adding seawater to top up it is important to check combined Chlorine and Superchlorinate if necessary