Swimming Pool Chemicals: FAQ

The following list of products are a suggested basic shopping list to keep in stock to cover everyday requirements during the season. There may be other products needed to deal with specific problems but these can be purchases as and when required.

• Chlorine Shock
• Chlorine or Bromine (either granules or tablets). (The use of a multi function product reduces the quantity of flocculant and algicide required).
• pH Increaser/pH Reducer
• Algicide
• Flocculant/Clarifier

Below are a few safety guidelines for chemical storage and use:

• Before using chemicals, read the labels and directions. Follow all instructions
• Keep chemicals out of the reach of children
• Maintain all original lids on chemical containers and make sure the lids are closed
• Do not stack different chemicals on top of each other
• Store chemicals in a clean, cool, dry, well-ventilated area, preferably off the floor
• Keep pool chemicals away from lawn and garden chemicals
• Keep liquid chemicals away from dry chemicals
• Keep separate all different forms of chemicals
• Wash your hands after using chemicals
• Never mix two chemicals together. Use a clean scoop for each chemical
• Always add the chemicals directly to pool water, either in a feeder, distributed across the surface of the pool, or diluted and poured into the pool waters
• Always add chemicals to water. Never add water to chemicals
• Never add chemicals to the pool with swimmers in the water.

All chlorine breaks down in water into hypochlorous (HOCL) and hydrochloric (HCL) acids. These are the active sanitizers, also called “free chlorine”

Chlorine Granules are higher in concentration, typically 60% of active sanitizers. Granules should be pre-dissolved in warm water and added directly to pool. Although the granules dissolve, the available chlorine is a slow release process, which enables the level to be maintained for a longer period. Recommended dose 85g per 10,000 gallons. Test water daily to ensure free chlorine level between 1.5 and 4.0 ppm, and increase dose as required.
Chlorine Tablets are simply compressed tablet forms of granules. Tablets are 200g. Tablets are added to skimmer – 2 tablets should last 1 week per 11,000 gallons.
Multi function chlorine tablets or granules have built in algicide and flocculant giving better water quality and reducing the amount of further algicide and flocculant required.
Shock chlorine should be used when the pool has gone green or cloudy. Shock is also required to raise the chlorine level to about 10ppm when opening/closing the pool, and every week whilst in use, this will totally sanitize the pool. Unlike normal stabilized chlorine, shock has very little “available chlorine” and will therefore dissipate quicker. Granules should be pre dissolved in bucket with pool water, before slowly pouring the solution directly into the pool, immediately above the return inlet. Add 650g per 10,000 gallons, but if algae present, double the dose. Wait at least 30 mins before using the pool. Ensure chlorine levels have dropped down to at about 3ppm before you use the pool again.

Waste enters the pool through wind, rain and people. Many of these wastes are not filterable and combine with the chlorine to form “chloramines”, a chlorine nitrogen complex. Chloramines cause eye irritation and reduce the amount of “free” chlorine available to provide sanitation. A build up of waste also causes the water to become cloudy and have a dull appearance. Shocking burns out wastes and transforms the chloramines back to free available chlorine. Shocking uses oxidation to restore the pool water to a sparkling, clean, comfortable condition. Normal chlorine levels are usually unable to accomplish this.

Shocking should be done every week. Heavy pool use and warm water temperatures will further increase the need to shock. The addition of 650g of chlorine shock per 10,000 of pool water is usually sufficient. Preferably shock the pool in the evening. Additional shock may be needed after heavy rain, particularly heavy use or hot weather.

Green water may be caused by metals, but more likely caused by algae growth. The solution is to check and adjust pH and total alkalinity. Once pH level is between 7.2 and 7.6, give a shock dose. If this does not clear water within 24 hrs, repeat treatment.

The use of algicide prevents algae growth in pools and is an important aid to keeping your pool clean. Whilst the chlorine you use for regular pool maintenance and water sanitization does have some algicidal properties, the addition of algicide will enhance and prolong the effectiveness of the chlorine and can give backup to the anti-algae effects of regular chlorination. If algae are present in your pool, despite your regular pool care routine, the use of algicide is definitely recommended.

There are many factors that can encourage algae growth, for example rain, falling leaves, temperature, sunlight, pH, and mineral content.

pH increaser is used to raise the pH level of the pool water to the ideal range of 7.2 to 7.6 ppm. Correct pH level is important, helping to reduce the amount of chlorine required. Recommended dosage is 10g per 1,000 gallons. Pre-dissolve and add whilst circulation system is running. Pour slowly above pool return inlet. Test pH daily and repeat dose until reading increased to 7.4. Never add whilst pool is being used, wait 30 minutes after dosing before allowing the pool to be used.

pH Reducer is used to reduce the pH level to the ideal range of 7.2 to 7.6 ppm. Having the correct level helps chlorine to fight bacteria and algae. Recommended dosage is 10g per 1,000 gallons. Pre-dissolve and pour slowly above pool return inlet. Add with circulation system running. Test pH daily and repeat dose until reading decreased to 7.4. Never add whilst pool is being used, and wait 30 minutes after dosing before allowing the pool to be used.

Total alkalinity should be between 80-140mg/1ppm. If your level falls below this, you will need to use Alkalinity Increaser. To raise total alkalinity by 10mg/1ppm add 16g per 1,000 litres of water (750g per 10,000 gallons). Ensure circulation system is running when adding this product. Pre-dissolve 200g in bucket of pool water before adding directly above pool return. Repeat as necessary, retest, and adjust accordingly. The pool water may cloud over temporarily.

Total alkalinity should be between 80-140mg/1ppm. If your level is higher than this, you need to lower the pH level by using pH Reducer. If this lowers the pH level too much, you then need to use pH Increaser to correct pH level, this will not affect Total Alkalinity

Calcium hardness should be between 175-225mg/1ppm. Calcium hardness is a measure of the amount of calcium dissolved in water. To increase the calcium level you will have to add calcium chloride.

In a soft water area the calcium level can be decreased by diluting with mains water (backwashing). In hard water areas no action is necessary.

Using flocculant will give you a sparkling clear pool, by improving the efficiency of your sand filter. Flocculant causes the fine particles, which could pass through the filter and make the water cloudy, to coagulate, enabling them to be removed by the filter. Add direct to water and leave overnight with filtration system on. Vacuum bottom of pool. Flocculant is aluminium sulphate

The following are the ideal water balance levels recommended.

Free Chlorine 1.0 to 3.0 ppm
pH 7.2 to 7.6 (ideal 7.4)
Total Alkalinity 125 to 150 ppm
Calcium Hardness 175 to 225 ppm

Metric:

Length in Meters x Width in Meters x Average Depth in Meters = Volume in cubic meters

Imperial:
Length in Feet x Width in Feet x Average Depth in Feet x 6.25 = Volume in Gallons.

Circular Pools:
Metric
Radius in Metres x Radius in Metres x Average Depth in Metres x 3.1428 = Volume in cubic meters

Imperial
Radius x Radius x Average Depth x 20 = Gallons

We recommend that you check pH is between 7.2 and 7.6, use a shock treatment, and then use either winter dosers, or a combination of winter algicide and chlorine.
Multi Function Winter Dosers give a continuous dose of chlorine, algicide and flocculant throughout the winter. Two dosers should treat a pool up to 11,000 gallons, four dosers for pools over 11,000 gallons.
If using Winter Algicide and Chlorine, then the algicide should be added after the pH has been adjusted and the water has been shock treated. Dosage should be 2.5l per 11,000 gallons. This dose should be repeated after 2 months. In addition, chlorine should be added at regular intervals to ensure free chlorine is kept at 1 to 1.5mg per ltr.

Putting a Winter Debris Cover on your pool at the end of the season stops falling leaves and other debris from polluting the pool over the winter. It will also stop chemicals from getting out, saving time when you open the pool next season

We just need your actual pool size to price for a Winter Debris Cover. The cover will be made with a 12” (60cm) overlap on all sides, so that the cover lays above the water. For freeform pool covers, we will need you to complete a pool survey form, available to download from the website.

I have received my Winter Debris Cover, now how do I fit it?

Firstly you will need to remove the cover from the storage bag. Then ensuring that it is the correct way up (anti wear strips facing down) lay beside the pool. Once you are happy that the cover is the correct size, lay the cover centrally on the pool and lay the straps out flat drilling 6mm holes at each strap position. The corner straps should be at 135° to the edge of the cover, all the other straps should be at 90°.
Buckle the stainless steel spring anchors to the strap and pin the ‘p’ pins into the drilled holes. Start at one end, tension the straps, then do the opposite end, and tension, and repeat along sides. The cover should not rest on the water, it should be tensioned to form a consistent seal with the pool deck, allowing leaves to be swept off.
How do I care for my Winter Debris Cover?

– Firstly you should make sure that the straps are tensioned to ensure that the cover fits well over the pool. Ensure that the cover does not come into contact with undiluted chemicals as they can bleach or cause damage, do not put chemicals through the cover. If chemicals need to be added, detach a corner and add to the pool, ensuring they are thoroughly circulated.
If excessive snow accumulates on the cover you should remove as soon as possible to avoid putting additional strain on the fixings. It is recommended that you allow no more than 28cm of snow to build up on an average sized winter debris cover.
At the end of the winter when you remove your Winter Debris Cover, you should remove all detachable fixings, as they may damage the material if rolled up in the cover, hose down with fresh tap water, and allow to dry thoroughly, then fold back into the storage bag. Store in a dry place away from rats/mice that could chew through and damage the cover. Pack fixings separately to avoid damage to the cover. Your cover should then be ready when for use next winter.