Sanitisers and Shock
All Swimming Pools and Spa’s should have a sanitiser added to treat Pathogens and is purely down to personal choice which you choose to use in your Pool or Spa.
Chlorine
This is the most common and popular way and can be stabilised or unstabilised (shock) and available in granular, tablet and liquid forms;
Granular – should always be mixed with warm water and added directly to the Pool
Tablets – should always be placed in the Skimmer Basket or dedicated dispenser
Liquid – added directly to the Pool.
Stabilised Chlorine – Granular or Tablet
The easiest and most effective way to treat your Pool. Stabilised Chlorine has stabiliser added to the Chlorine, usually in the form of Cyanuric Acid. The stabilised element is the part that stops the Chlorine from immediately being burnt off by the Sun, thus allowing it to stay in the water and be ‘used up’ killing Pathogens rather than disappearing through evaporation.
Unstabilised Chlorine (Shock) – Granular or Liquid
When adding any form of Chlorine Shock, the cover should be removed and no swimming for 48 hours.
Granular Shock (Calcium Hypochlorite)
Granular Shock is Chlorine that doesn’t have stabiliser added to it. This means that it’s a short acting chemical that is burnt off quickly. It raises the Free Chlorine to a very high level and takes between 24-48-hrs to burn off. Granular Shock is for use every 2 – 4 weeks in a Pool to kill any Chloramines that may have formed. Adding Shock will kill the Chloramines and allow the Stabilised Chlorine to continue working correctly. Although Granular Shock is strong, it is not strong enough to kill any Algae that has formed. It will bleach it and make it look like it has cleared but it will in fact return. Granular Shock is for use as a regular maintenance throughout the months your Pool is open.
Liquid Chlorine (Sodium Hypochlorite/Liquid Shock)
Liquid Chlorine comes in different percentages of strength, the most common for Pool use is 14/15%. Like Granular Shock, it is not stabilised and will burn off after 48hrs. Liquid Chlorine should be used when Summarising and Winterising your Pool and when there is an element of Algae. To treat Green Algae, the normal dose for a green Pool is 20 litres per 10,000 gallons but this does depend how green the Pool is. To treat Mustard Algae, in this instance is little and often. Depending how bad the Algae is, ideally 5/10 litres per week for 6 – 8 weeks (dependant on size and conditions).
Fi-Clor Superfast Shock Granules (Calcium Hypochlorite)
This product is very similar to Liquid Chlorine but is much easier to transfer and used to treat Green Algae. This product contains 15% more Free Chlorine than Granular Shock.
When testing the Chlorine level in your Pool or Spa, you will have a reading of Free Chlorine, Total Chlorine and Combined Chlorine and Total Chlorine;
Free Chlorine - the amount of Chlorine available to sanitise your water
Combined Chlorine - the level of Chlorine that has already been ‘used up’ sanitising your Pool
Total Chlorine - Free Chlorine and Combined Chlorine added together.
Bromine
A non-chlorine alternative sanitiser most commonly used in indoor Pools and Spas/Hot Tubs due to its stability in higher temperatures. Bromine is unstabilised and available in granular and tablet form.
Granular – should always be mixed with warm water and added directly to the Spa/Hot Tub
Tablets – should always be placed in the Skimmer Basket or a floating dispenser when using in a Spa/Hot Tub.
Bromine is expensive to use but is more beneficial for people with sensitive skin and eyes. As Bromine is unstabilised, it will burn off quickly by the Sun when used in an outdoor Pool.
Unstabilised Chlorine (Shock) – Granular or Liquid
When adding any form of Chlorine Shock, the cover should be removed and no swimming for 48 hours.
Granular Shock (Calcium Hypochlorite) – when used with Bromine
When using Chlorine Granular Shock in a Bromine Pool or Spa/Tub, it reactivates the Bromine Ions into Free Bromine (reusable Bromine) molecules to remove contaminants that might have escaped during normal daily Bromine dosage.
Granular Shock is Chlorine that doesn’t have stabiliser added to it. This means that it’s a short acting chemical that is burnt off quickly (24-48hrs). During this time, it raises the Free Chlorine level very high to allow the Bromine to reactivate and continue dosing your Pool or Spa. Granular Shock is for use every 2 – 4 weeks in a Pool. Although Granular Shock is strong, it is not strong enough to kill any Algae that has formed. It will bleach it and make it look like it has cleared but it will in fact return. Granular Shock is for use as a regular maintenance throughout the months your Pool is open. There are non-chlorine shock treatments available should you prefer to use this instead.
Salt
Salt is an alternative to using Chlorine in granular, tablet or liquid form. To be able to use Salt as a sanitiser, you will need to have a Salt Water Chlorinator as part of your system. The Chlorinator simply turns Salt into Chlorine which is a chemical reaction caused by using electricity. As there is no stabilised element to the Chlorine created, you should add a stabiliser in the form of Cyanuric Acid. This level should be between 60 – 80 ppm for Salt Water Pools.
Unstabilised Chlorine (Shock) – Liquid
When adding any form of Chlorine Shock, the cover should be removed and no swimming for 48 hours.
When using a Salt Water Chlorinator, you don’t need to use Granular Shock (Calcium Hypochlorite) as you have the ability to raise the output of Chlorine into your Pool.
Liquid Chlorine (Sodium Hypochlorite/Liquid Shock)
Liquid Chlorine comes in different percentages of strength, the most common for Pool use is 14/15%. Like Granular Shock, it is not stabilised and will burn off after 48hrs. Liquid Chlorine should be used when Summarising and Winterising your Pool and when there is an element of Algae. To treat Green Algae, the normal dose for a green Pool is 20 litres per 10,000 gallons but this does depend how green the Pool is. To treat Mustard Algae, in this instance is little and often. Depending how bad the Algae is, ideally 5/10 litres per week for 6 – 8 weeks (dependant on size and conditions).