The Aspects Pools Blog Advice and Product Reviews from Swimming Pool Experts

March 6, 2015

Swimming pool water treatment – Cloudy Water

Filed under: Prevention & Cure Chemicals,Swimming Pool Chemicals — admin @ 10:22 AM



Cloudy water could be due to a number of factors:

High total alkalinity or pH which bring hardness salts out of solution, low free chlorine allowing a build-up of bacteria, poor filtration which is ineffective at removing particles suspended in the water, or the start of an algae bloom.

The use of a test kit or test strips may help to establish the most likely cause.

Probable causes

• High pH and/or total alkalinity

• Low free chlorine level

• High stabiliser (cyanuric acid) level

• Poor or inadequate filtration

What you may need…

pH & Alkalinity Reducer to correct high pH and/or alkalinity

Fast acting chlorinator to shock chlorinate the pool

Fast acting Clarifier to clarify the pool water after killing the algae

• Clarifies and helps prevent algae

• No vacuuming required

• Adds sparkle to water surface

• No sulphates to attack grouting and render

Water Balance with a little help from Aspects Pools

Water Balance with a little help from Aspects Pools


Action to be taken

1. If due to high pH and/or alkalinity

• The pH tells us whether the water is acid or alkaline and requires checking on a regular basis. It should be maintained in the range 7.2 – 7.6. If the pH is above 7.6, lower it by dosing pH & Alkalinity Reducer at a rate of 500g per 50m3 (11,000 gallons). With the circulation running, distribute around the pool, avoiding the skimmers. Do not dose it in one spot otherwise some alkalinity may be destroyed.

• Alkalinity should be kept between 80 – 150mg/l (ppm). If necessary it can also be reduced using pH & Alkalinity Reducer. Your approved chemical dealer will be able to test a sample of your pool water and advise on a suitable dosing procedure.

2. If due to low free chlorine

• NOTE: The free chlorine residual should be maintained within the ranges 2.0 – 4.0mg/l (ppm) for stabilised and 1.0 – 3.0 for unstabilised chlorine products, even when the pool is not in use.  If you are using Chlorine Granules, you will need 90g per 50m3 (11,000 gallons) to provide 1mg/l (ppm) and 64g for Shock Granules.

• Shock chlorinate the pool using either liquid or granulated shock. Add the contents of one entire 450g shock pot to 50m3 (11,000 gallons), or pro-rata* for other pool sizes. This will raise the chlorine level by approximately 7mg/l (ppm). Broadcast the required quantity across the deep end of the pool with the circulation pump running.

*Approximately 64g per 50m3 (11,000 gallons) will increase the free chlorine by 1mg/l (ppm).

3. If due to high stabiliser level

• Stabiliser is essential in an outdoor pool but if you are using either stabilised chlorine granules or Tablets (including multi-functional products), the stabiliser level may well increase depending on the level of water replacement. Take a sample of your pool water to your approved chemical dealer who will test it for you and advise how much water you will need to replace with fresh. Due to structural considerations relating to the pool design etc, great care should be exercised when draining large quantities of water and the advice of your dealer should be sought regarding the maximum quantity of water that it is safe to replace in one operation. The stabiliser level should be between 30-60mg/l, but ideally at the lower end of this range following a water replacement.

4. If due to poor or inadequate filtration

• It is good practice to have the quality of the filter media checked every 2 years. The correct depth of media is essential if your water is to remain free from small suspended particles. Your approved dealer will be able to advise on all aspects of filtration equipment and maintenance.

• Ask your dealer to check that there is a good flow of water being taken from the bottom drain of the pool.

• The filter may be aided in the removal of very fine suspended particles by the use of a Rapid Clarifier. Add an initial dose of 200ml per 50m3 (11,000 gallons). To keep the water sparkling add a routine dose of 100ml per week. Alternatively you could use Clarifier Tablets, 1 sachet per 50m3 (11,000 gallons).

Feel free to call or email us for further assistance – ALWAYS READ THE LABEL prior to use of any chemicals.

No Comments

No comments yet.

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.

Powered by WordPress