Guide for swimming pool chemicals in Thailand  

Links to contents:

Introduction & disclaimer
Algicides
Algicides with flocculant (clarifier)
Flocculant (clarifier)
Ionization
pH regulator
Alkalinity
Water hardness
Chlorine
Other chemicals (iron and stain removers, disintectant cleaners)

Disclaimer: All swimming pools in Thailand are different, there are many factors affecting your water chemistry. This guide is provided 'as is' based on SwimmingPoolsThailand's more than 20-year experience with tropical pools, and recommendation made by various governments. We accept no responsibility for its use and do not guarantee the performance of the products listed.

TESTING: Test strips are not perfectly accurate. Fine for small pools, but for the the best results, use digital meters, or traditional inexpensive pool test kits for pH and Chlorine. See water testing.

All our own brand 'Kleer' products and our dry chemicals have instructions on their product pages and in English, French, German and Thai on the labels.
If you don't find your answer here, create an account and get a free PDF copy or view the fully searchable online interactive version of our General Catalogue. It's packed with more tips and tricks for pool care. Don't hesitate to contact us through our contact form for more free advice in English, French, German, and Swedish.

In some areas especially Isan,  and Koh Tao, you can book a  visit from one of our pool technicians at a very reasonable fee. He or she will test your water professionally, check your systems, and send you a full report.

ALGICIDES

Simply killing the algae is not enough, it has to be removed to prevent any live spores from reproducing again. Thoroughly clean the affected areas with a stiff nylon or wire brush, vacuum any visible debris and treat the water with a floculant to filter out any remaining particles.

Green algae turns water light green. If untreated, the water will soon become a thick, dark green soup.  It is the most common form of algae and it's what you'll find when you return to Thailand after an absence of several weeks. It can happen very quickly, even overnight after a tropical storm but it is not difficult to treat. If left too long however, the most economical solution is to change the water and thoroughly clean the floor and walls and flush the plumbing.

Generally the correct level of chlorine will prevent green algae, but if it recurs often, use regular dosing of GreenKleer or install an ionizer. Algicides will not remove the green colour; the dead algae must be removed with a floccuant to clarify the water. Some of our products are a combined algicide-flocculant.

See GreenKleer, an economical and highly effective non-foaming algicide. Immediately kills green algae.  See also AquaKleer for pools with cartridge filters and D.E. filters.

Mustard and Red Algae are a slime or powder that sticks to the walls, steps, and ladders. They are more rare than most strains but are resistant to chlorine. See VerdiKleer for Mustard algae and most  other strains.

Black Algae is quite common but difficult to destroy. It generally appears on grout that is not special grout for pools. In the worst case scenario, if left too long and the grout was not a high quality polyester based two-component grout, black algae grows down into it and you end up having to drain and regrout the pool.

Use AlgiKleer for black algae. This is a short  sharp treatment for black algae which grows on the grout between the tiles and is very hard to destroy. It works best on its own - do not mix with other SPTpools or other brands of algicides.
Black Algaetrine, like AlgiKleer is a commercial strength algicide for high use, large and commercial pools.

Once a pool has been blighted by black algae, you will always need to regularly dose the pool water as a preventative and remove the dead spores. KristalKleerPLUS  contains an algicide and clarifies the water by removing the dead green algae which is still giving the water its green colour.

ALGICIDES with FLOCCULANT (clarifier)
After using an algicide-floccuant, the powder that settles on the pool floor must be vacuumed to the waste setting on the filter valve followed by a good rinse of the filter. KristalKleerPLUS is a combined algicide-flocculant ideal for domestic and smaller pools up to around 60m3 (a typical 4 x 10m pool). For larger pools, use separate algicides and flocculants.

 Be sure to use AquaKleer algicide + clarifier for D.E. and cartridge filtration systems.

IONIZATION
One very effective alternative for killing algae and at the same time sanitise the pool, is to install a ClearBlue mineral ionizer. Easily installed in less than 30 minutes and costing less than a year's supply of chemicals for a medium sized family pool, an ionizer relieves you of the guesswork and much of the tedious maintenance. They will also save up to 90% on chlorine. Entirely harmless and fully environmentally friendly, an ionizer does not inject any chemicals into the water. The silver, copper, and zinc ions released into the water are today's state-of-the-art solution for algae-free and correctly disinfected water.
UV systems are also an excellent alternative to sanitation by chlorine. They need additional plumbing, valves, and space, and should preferably be installed by a pool professional. They are nevertheless also reasonably priced. See our Emaux UV sanitisers.


FLOCCULANTS (clarifiers, the same products are sometimes marketed more expensively as 'brighteners')
Flocculants clarify the water. They cause microscopic suspended impurities to coagulate into larger particles and then settle to the floor of the pool to be filtered out more easily. They do not remove dissolved minerals such as salt, iron, manganese etc. They are available as powders and liquids. Clarifiers should be left to work over night. The pool floor should then be vacuumed followed by a backwash and rinse of the filter  If using after a treatment for algae, vacuum the pool to the 'waste' setting on your filter valve.


KristalKleer liquid water clarifier. Excellent quality - super low price. Recomended for domestic pools. Safe to use. Not for use with cartridge or D.E. filtration  systems.
KristalKleer-PLUS liquid water clarifier + algicide is one of Thailand's best selling pool products. Not for use with cartridge or D.E. filtration  systems.



Flocculant (water clarifier) Granules is flaked aluminium sulphate. Often marketed at excessively high prices, it's the most economical of all water clarifiers. For clarifying cloudy or dirty water.
 Not suitable for use with cartridge or diatomacious earth (D.E.) filters. Safe to use.  For very rapidly clarifying cloudy, green, or very dirty water, use FlocculantPLUS premium water clarifier powder.  Safe to use. Not for use with cartridge or D.E. filtration  systems.
  For D.E. and cartridge filters, use 
AquaKleer algicide + clarifier, it eliminates green algae and increases water clarity.

PH REGULATOR
In order for any kind of pool sanitation system to work, whether it is chemiclal, mechanical, or electronic, the water pH must be between 7.2 and 7.6. The pH level indicates the relative acidity or alkalinity of your pool water. pH is measured on a scale from 0 (strong acid) to 14 (strong alkaline) and pH neutral is 7. In pools, a slightly alkaline level between 7.2 & 7.6 is ideal because apart from being he range in which the water can be disinfected, this range is the most comfortable to the human eye, provides optimum use of free chlorine and provides water that is not corrosive or scale forming.
If the pH is too high, add pH Minus (dry acid) 10g per day (per 1000-litres) until the pH has decreased to between 7.2 and 7.6.
If the pH is too low, add pH Plus (10g per day (per 1000-litres) until the pH has increased to between 7.2 and 7.6.
A simple test kit for pH is not expensive and will also test the chlorine level. Our  premium grade pH Minus is a granular pH reducer made in Germany. Much safer and easier to use and store than liquid Hydrochloric acid (Muriatic acid). Best for manual addition to pool water. 

Read more about lowering pH and how to do it in our special article: How do I lower the pH in my pool?

To raise the pH, use pH Plus. No fumes, no storage problems. Supplied in plastic tub. Contains Sodium Carbonate (Na2CO3). Harmless if swallowed, it is also an ingredient in toothpaste and sherbet powder.



ALKALINITY
The level for Total Alkalinity (TA) should be between 80 and 140 parts per million (ppm). Total Alkalinity is a measure of water’s resistance to change in pH – TA is the amount of alkali (not to be confused with alkaline) in the form of bicarbonates, carbonates and hydroxides present in the pool water. TA affects and controls the pH.
Total Alkalinity (TA) represents the ability of the water to resist changes to the pH level. Ideal Alkalinity will prevent pH 'bounce' and avoid damage to tile grout and tile adhesive. Ideally TA should be between 80 and 120. Over 120 may cause cloudy water. Under 80 will cause the pH to bounce and will damage equipment.
Total alkalinity should only be lowered when it causes a significant rise in pH levels, or when it causes calcium scaling through CSI.

Lowering: To lower pH and total alkalinity, use a strong acid such as hydrochloric acid (muriatic acid), sulfuric acid or pH minus which  is much easier and safer to  use, all of which lower both pH and TA, but at different rates.
Raising: Sodium bicarbonate (baking soda, NaHCO3) 500 gr will raise 40,000 liters of water 10 ppm. It will raise the total alkalinity without excessively raising the pH. Our 1 kg and 4 kg packs are available at a fraction of the price of purchasing tiny sachets of baking powder from the supermarket. Not to be confused with sodium carbonate (soda ash) pH raiser.

HARDNESS
The water hardness should be maintained at a minimum level of 200ppm. Calcium above 400ppm can cause scale to form and leave limescale deposit on the tiles and fixtures and fitting and cause corrosion. It can also damage technical equipment such as salt water chlorinator cells, and despite the moving parts and high velocity of the water, it can also  build up inside the pump. Water that is too soft (uncommon in Thailand) will leach calcium out the tile grout and eat the grout away.
An excessive amount of pool chemicals can cause your water to be cloudy. That includes: high pH, high alkalinity, high chlorine or other sanitizers, and high calcium hardness.

Prolonged untreated water will cause the tile adhesive to dissolve, leaving loose tiles. To reduce some of the water hardness, use a flocculant to rid the pool of free-floating calcium carbonate. Vacuum the walls and floors to remove calcium carbonate particles. Backwash or clean out your pump filter.

There are no chemical methods for reducing water hardness

. The only way to fully reduce water hardness is to drain some of the water and dilute the existing pool water with fresh water. This will not help if you are filling your pool with well water that is already hard, in which case you should consider the installation of an ion exchange water softening system.

To increase water hardness use Calcium Chloride flakes. Use about 750 gr of calcium chloride per every 40,000 liters of water to raise the hardness by 10 ppm. 


CHLORINE PRODUCTS
See also our extensive Guide to Using Chlorine.
Our chlorine products are listed in their own category.  Chlorine is the most commonly used pool sanitiser. It is important to maintain the correct level of chlorine at 0.5 to 1.5 ppm.  For domestic pools, a simple test kit is not expensive and will also test the pH. Adding chlorine is best done at dusk to avoid the sun's UV rays, and to allow the chlorine to work over night.



Nissan 90% TCCA stabilised chlorine GRANULAR. Very high quality. Available in 50 Kg and 20 Kg drums.



Nissan 90% TCCA stabilised Chlorine POWDER. Very high quality. Available in 50 Kg and 20 Kg drums. 

Nissan Hi-Lite 90% TCCA stabilised shock chlorine POWDER



Nissan Hi-Lite 90% TCCA stabilised shock chlorine GRANULAR  and POWDER. 7 kg. Very high quality. 



PoolChlor 90% TCCA stabilised chlorine available as GRANULAR, POWDER, and 3" TABLETS. The next highest quality brand of chlorine available in Thailand. No wastefull fillers or binders. 

 



Dichlor 60%. SDIC stabilised poolshock GRANULAR Ideal for for shocking pool with salt water chlorinators, or starting a new pool or a newly filled pool.



Calcium Hypochlorite 65% non-stabilsed pool shock POWDER Non-stabilised fast-acting chlorine 65% for shocking pool water without increasing the CYA level.



Cyanuric  acid is a chlorine stabiliser in normal T.C.C.A stabilised chlorine for pools, and if you are adding chlorine at dusk, you probably do not need CYA. CYA prevents the sun's UV from burning up the chlorine too fast. Add CYA to your pool water only if you are using a salt water chlorinator system and filtering your pool in the hours of daylight. The optimal range for CYA is 20-50 ppm, although a study by University af California indicates that there is still significant savings in chemical costs in levels as low as 2 or 3 ppm. CYA does not dissipate, adding more accumulates it. Too much of it can actually block the sanitising effect of chlorine - exactly the opposite of what you want. CYA is also very expensive. Read more in our CYA Fact Sheet.



OTHER CHEMICALS stain removers, filter cleaners, toilet & terrace disinfectants



FilterKleer swimming pool filter cleaner and degreaser for cleaning, regenerating, and rinsing sand, Zelbrite, glassmedia, D.E. grid elements, and cartridge filters.


Pool Salt TRS (Blue bag)
 Specially refined for use in swimming pools with salt water chlorinators, and brine bath spas. From Asia's largest salt mine - in Thailand. TRS pool salt does not contain any additives that can damage the thin coat of titanium on the chlorinator cell electrodes. Using other salt or table salt will shorten the life of the electrode. Never use salt in the TRS red or orange bags (some pool stores will try to sell you these), it is industrial food grade and table salt. Electrodes are very expensive to replace. 


SteriKleer disinfectant is an essential cleaner for commercial and heavily used private pool surrounding areas. Disinfectant, fungicide, bactericide, and deodorant. Removes dirt, grime, grease and oils, preventing odour, and kills germs. Ideal for use on pool walls, steps, slides, spas, decks, patios, showers, and toilets. Kills many bacteria including Staphylococcus aureus and Salmonella typhosa.

 Not for adding to pool water.

CheliKleer stain & scale remover. Prevents and removes stains and scale by chelating and sequestering minerals such as iron, calcium, and manganese. However, serious cases of unwanted metals and minerals will require the installation of a filter filled with Manganese Green Sand media.

StainKleer sprinkle StainKleer evenly around the water. Use 500gr of StainKleer for every 40,000 litres of water. See product page for full details.
NOTE: CheliKleer and StainKleer work particularly well with each other.

MANGANESE GREEN SAND is a zeolite filter medium. It is used for removing heavy iron, manganese and other metallic elements from well water. It is used as a filtration medium in well water filters and removes the odour of hydrogen sulfide (rotten eggs).

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