Archive for the ‘Swimming Pool Chemicals’ Category

swimming pool winterisers – a cost comparison

Tuesday, August 23rd, 2011
Every autumn pool owners buy their winterising chemicals but how many of them study the label and take note of the recommended doses?


Winterising chemicals can come in 5 litre, 3 litre, 2 litre or 1 litre bottles and they all have different pool volumes that they can dose.


Despite what it may say on the lablel, winterisers will last for about 3 months so to get 6 months of protection you will need to dose your pool twice. Once in October and again in January.


The contents are mostly water with the “good stuff”, the algicide, in varying concentrations. So to cut through the confusion we have come up with our pound cost dosage comparison. We have standardised our pool volume to 10,000 gallons and our longevity to one 3 month span.


You don’t have to use winter algicide, some summer algicides will do the winterising job just as well so we have included them too.


Reading across the table Perfect Super Concentrate comes in a 1 litre bottle and will treat 26,000 gallons. That means you need  0.4 litres to treat 10,000 gallons. At a cost of £24.00 for 1 litre that means it costs £9.60 to treat 10,000 gallons. Compare that to the popular Kleen Pool Brand and you’ll see it costs £22.50 to treat 10,000 gallons.  Worse still is Clear n Clean at £30.00 per 10,000 gallons.  That is why we don’t sell them!


Chemical name Container size Gallons container will treat Litres required to dose 10,000 gallons Container
Cost		 Cost per 10,000 gallons
Perfect Super Concentrate 1 litre 26,000 0.4 £24.00 £9.60
Champion Winterclear 5 litres 12,000 4.2 £21.00 £17.64
Blue Horizons Wintertime 5 litres 15,000 3.3 £21.00 £13.86
Fi-Clor Winteriser 3 litres 19,000 1.6 25.00 £13.15
Kleen Pool 1 litre 5,000 2.0 £11.25 £22.50
Clear n Clean 1 litre 6,000 1.6 £18.00 £30.00
Blue Horizons Algimax 2 litres 20,000 1.0 £18.50 £9.75


We sell the top 3 on the list. Two dedicated winterisers (Perfect Super Concentrate and Fi-Clor winteriser) and the all year rounder Blue Horizons Algimax Eliminator.

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What is Available Chlorine?

Thursday, August 4th, 2011

On the label of most swimming pool chlorine products you will see a reference to “Available Chlorine”. This short article will attempt to explain what that is.

In its natural state of 100% purity chlorine is a gas but  swimming pool chlorine is often refered to as “granular chlorine” or “shock chlorine” or “chlorine tablets” “or “liquid chlorine”.  In order to get from a highly poisonous gas to a stable white powder you have to add stuff. The more stuff you add the lower the content of chlorine becomes until it is low enough to remain stable in the container and for general handling.

Chlorine Tablets contain chlorine in the form of trichloroisocyanuric acid (short name “trichlor”). This is the most concentrated form of swimming pool chlorine with a 90% available chlorine level.

Next comes Shock Chlorine which is calcium hypochorite (short name “cal hypo”). The strength of this can vary, as a minimum it is 65% available chlorine, but some of the fi-clor  superfast blends are 75% available chlorine.

Granular chlorine has a few different chemical names but is best known as sodium dichloroisocyanutrate (short name “dichlor”). This has 55% available chlorine.  Granular chlorine and chlorine tablets contain cyanuric acid which is a stabliser to stop the chlorine being burnt off by the sun.

Liquid chlorine, like shock chlorine, does not contain cyanuric acid stabiliser. Liquid chorine is sodium hypochlorite and contains about 15% available chlorine. Other forms with 10% or lower concentrations are available and are used by dairy farmers for sterilisation and in household bleach.

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How salt water chlorination works in swimming pools

Friday, July 22nd, 2011

Most people will know that that the best chemical for killing algae and bacteria in swimming pool water is Chlorine.


Most people will know that salt is Sodium Chloride, a Sodium atom bonded to a Chlorine atom. Chemical Symbol NaCl.

Most swimming pool owners know that they have to regularly buy “Chlorine” granules and throw them in their pool to kill algae and bacteria to keep their pool water clean and safe to swim in. It gets used up and you have  to go and buy more.

The more savvy pool owner will know that one of the types of  “Chlorine” he could use is actually Sodium Hypochlorite and when he adds it to water Hypochlorous Acid (HOCl) is formed and that is what actually kills stuff.  Sodium Hypochlorite  sounds a bit like Sodium Chloride – salt. Well it is close, but just putting salt in your pool will not kill bacteria  – you have to “hypo” it. To “hypo” it you have to add an Oxygen atom.  If you mix a lot of water (H2O) and little salt (NaCl) together and pass and electric current through it, greatly simplified, an Oxygen atom and a Hydrogen atom join up with a Chlorine atom and you get H + O+ Cl = HOCl, hypochlorous acid. Bingo! All bacteria dead and lovely clean pool water. That really is just about all there is to salt water chlorination except read on because it gets even better.

Strickly speaking it is not Chlorine that kills bacteria or algae it is the Oxygen that does the killing by oxidising the bacteria, the same reaction as burning something. Burning, setting fire to and oxidising are all the same thing, either way the bacteria is dead. So the Hypochlorous acid gives up its oxygen atom to burn the bacteria and the chlorine atom goes back in to the water. That is until it finds its way back to the electrodes of the salt water chlorinator and re-forms in to HOCl again and goes off looking for more bacteria to kill. Self regeneration, a never ending supply of hypochlorous acid means you never have to add sanitising chemicals to your pool water again.

So it is not hard to see why salt water chlorination is an ever more popular way to sanitise a swimming pool. Just add salt to the water and fit a set of clever electrodes called a salt water chlorinator and you can have pristine clean pool water and no need to add sanitising chemicals ever again. The high electrical current between the electrodes will also kill any algea spores in the water so although the hypochlorous acid would have got them anyway the electrodes killing them off mean you can lower the chlorine level down to about 0.5 ppm.

That is a brief explanation of how salt water chlorination works in swimming pools. Read the next article for the pros and cons of actually buying, fitting and using one.

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The pros and cons of salt water chlorination for swimming pools

Friday, July 22nd, 2011

In Australia and South Africa nearly all the domestic swimming pools are sanitised using salt water chlorinators. In the UK very few swimming pools use salt water chlorinators. The Aussies think we are crazy not for using salt water chlorination, so what are the pros and the cons?

At PoolStore we have recently become converts to the idea of salt water chlorination. This is mainly down to the introduction of a new product that means you can retro fit a salt water chlorinator to your pool wheras before the units were installed when the pool was first built or had to be installed by a pool professional.

The biggest and most obvious advantage of salt water chlorination is that you never have to add any chemicals to your pool ever again. Cleaning chemicals that is – chlorine, algicides, clarifiers will be a thing of the past. All you will need is pH balance chemicals now and then. No more pulling back the cover and finding the water has gone green since you last looked at it. Provided you don’t switch it off your salt water chlorinator will keep your water pristine clean all season.

The water will “feel” much nicer. This is a difficult concept to explain but the water will feel softer and more inviting. Because the salt content is much closer to that of your eye water, red eyes and eye irritation will be greatly reduced. Your fingers will not go as “wrinkly” due to the salt content and you will not come out of the pool smelling of chlorine.

So with pristine clean water for ever and no chemicals what could possibly be the downside to salt water chlorination? Well not much really. Despite what the manufacturers might claim, the water does taste salty. Not very salty,  at 10 times less salt than the sea it is not unpleasant, and after a few weeks regular users will get used to the taste and barely notice it at all.

The installation process involves putting a lot of salt in your pool. Eight 25kg bags for a 50m3 (11,000 gallon) pool. But at least you only have to do it once. You will need to keep a few bags of salt on hand because as you top up after backwashing or evaporation you will need more salt sooner or later.

The biggest disadvatage is the cost. For a 12 x 24 pool a salt water chlorinator will cost about £850.00 and the salt will cost about £100.00.  That is about 10 years worth of chemicals but factor in never having to go out there and dose your pool, except for the pH now and then, and the pay back may well seem to come a lot quicker.

We like the Zodiac EI salt chlorinator because it can be retro fitted to just about any pool.

The Zodiac EI salt water chlorinator is our favourite

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Why algae grows in your pool in the summer

Friday, May 27th, 2011

This is an article about algae in swimming pools and it has got graphs in it. I am sometimes accused of being a bit nerdy, I don’t know why!

Algae need light to grow, strong sunshine is algae’s best friend. Just when we are getting our pools ready for the warm summer days the daylight hours start to increase, just what the alage need. It is worth taking a look at just how the light in the UK varies throught the year.

Below is a  graph on which the blue line is daylight hours.  Note how all through June and well in to July we get 16 hours of daylight per day compared with 8 hours in winter. Twice as much daylight in summer as in winter.

The Blue line is daylight hours, the Red line sunset time, the orange line sunrise time

The next graph shows the altitude of the sun. Note how in summer when the days are 16 hours long the sun is up to 60 degrees above the horizon but in winter is barely gets above 20 degrees. The lower the altitude the more atmosphere it has to penetrate, the lower the strength of the light. The opposite in summer lots of light and lots of strength.

The higher the sun the stronger the light



That is why algae grows so much more in the summer than it does in the winter. Light = food for algea, give something twice the amount of food and it will grow twice as much.

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Chlorine kills 99.9% of all germs – what about the other 0.1%? Flocculation is the answer.

Wednesday, October 13th, 2010

Although this is much more of a concern for large commercial pools it is important for domestic pool owners to understand the potential risks.

Despite Chlorine’s ability to kill just about anything organic there is one type of nasty that evades being killed by chlorine. Well two actually  - Cryptosporidium and Gardia but they are very similar. They are a protozoan organism that forms a hard, impermeable shell around itself that is resistant to attack from Chlorine.  The shell is called an oocyst and if ingested by a human it can cause severe diarrhoea. It is passed on via contact with said diarrhoea.

So if the oocysts get in to your pool and Chlorine will not kill them – what can you do? Well the good thing from our point of view is that the oocysts are quite big, 6 thousandths of a millimetre. That might not sound big and it is still small enough to pass straight through a sand filter but it is big compared to a bacterium. So we can use flocculation to get rid of them.

Flocculation is the process of combining lots of small items together to form one bigger item, like snowflakes combining to form a snowball.  Adding a flocculent to the water makes all the oocysts combine in to bigger lumps and those lumps will get held back by the filter.

The cheapest and most common form of flocculent used is Aluminium in the form of Aluminium Sulphate.  This is what is in Granular Floc and Floc Tablets.  Environmental authorities are not keen on Aluminium being dumped in to water courses from your backwash but there are two flocculants that are better and Aluminium free. The first is based on polyacrylamides and comes in gel form. Jolly Clear Cubes are such a flocculent. Better still is Sea Klear Clarifier. It is not only gathers up oocysts and any other contaminants it also gets rid of oils and oily scum from suncreams that can cause stains on your liner.

So in the armoury of the pool owner the main weapon is chemical sanitisers, Chlorine being the most popular one but we should not forget the importance of flocculation to get rid the nasties that chlorine cannot reach.

Natural Sea Klear Clarifier

Natural Sea Klear Clarifier

jelly clear cubes

Jelly Clear Cubes

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Bayrol withdraw Duo Tabs from sale

Tuesday, August 10th, 2010

Bayrol have annouced to the trade that they are withdrawing their non-chlorine alternative Duo Tabs from their range. Users of Duo Tabs are being advised to change to Soft & Easy.

Duo Tabs were introduced to the market 20 years ago and ten years ago Bayrol brought out Soft & Easy. The two products are essentially the same. The chemical make up is the same but one is in tablet form, the other in granular form. Because the tablets came out before the granules they built up a loyal following but here at PoolStore we sell 3 times as much of the granular product as we do the tablet form.

The cost implication to the change over should be favourable. Based on a 60 cubic metre pool with Duo Tabs you would use 2 tablet pairs per week at a cost of £12.66. With Soft and Easy you would use 3 sachet pairs at a cost of £9.19

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The top four ways to kill algae in a swimming pool

Friday, August 6th, 2010

Algae growing in a swimming pool is a perenial problem for the swimming pool owner here we will examine the 4 most popular ways to get rid of it. These are

  1. Chlorine
  2. Copper
  3. Quats and Poly Quats
  4. Phosphate removal.


As we will see some of the above can be used to kill algae and some are only useful to prevent it forming in the first place. Algae can be introduced to the pool by rain, falling leaves, wind or even bathing suits transfering algae from one body of water to another. Planktonic clean water algae float on the surface of pool water while other types will attach and grow onto the pool floor or sides.  Many factors affect the development and growth rate of algae. Water temperature, sunlight, pH, mineral content and lack of chlorine residual of the pool water will all help to encouage algae development.

Chlorine.

Chlorine gets a bad press but since it was discovered that chlorine kills germs its use as a sanitiser in drinking water has saved millions of lives worldwide. Chlorine is the only chemical that acually kills algae. It acts in the same way as setting fire to the algae, it oxidises it.  When you have a bloom of green algae in your pool then by far the best thing to do it to blast it with a shock dose of unstabilised chlorine. What is not used up in killing the algae will be burnt off by the sunlight.

Copper

Copper does not kill algae it disrupts its metabolism and stops it reproducing. Copper can be introduced in to the water in two main ways as a chemical or by an ionizer. Too much copper can cause stains on concrete pools so chemicals that contain copper also contain a chelating agent, a stabiliser, that does not allow too much copper in to the water at any one time.

Quats and Poly Quats.

Quat is the short hand term for a family of chemicals called quaternary ammonium compounds.  Again they do not kill algae they disrupts its metabolism. Quats are short lived and you need to keep adding them to the water to keep algae at bay. They are a cheap chemical but they affect the surface tension of the water and cause it foam, foaming is perfectly normal but many pool users don’t like it. A high level of Quat will kill off an algae bloom but even so chlorine is still better for this so quats are usually used at lower levels as a preventative. Poly Quats or polymeric quaternary ammonium compounds are long chains of Quats and although they are more expensive they last longer and don’t cause foaming of the water. These are marketed as Long Life Algicides and are the popular form of Algicide in liquid form.

Phosphate Removers

All of the above chemicals act by meeting the algae head on and killing it. Phosphate removers act in a more subtle way. Algae must have phosphates present to be able to grow. Remove phosphates from the water and the algae are starved to death. Compounds of Lanthanum are used to react with the phosphate and precipitate it out where it is picked out by the filter.

All of the above methods are good at killing or preventing algae and you can mix and match any of them or even use all four methods.

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Does using Bayrol Soft & Easy mean saying goodbye to Chlorine?

Friday, August 6th, 2010

PoolStore’s recommended non-chlorine alternative is Bayrol Soft and Easy.  For a comprehensive article on all the various non-chorine alternatives read our help and advice section on the main website. We like the Bayrol product because it is easy to use but it has a few shortcomings and this article will explain them.

Firstly let’s just re-cap on why you put chemicals in your pool. Two reasons. (1) to kill bacteria. (2) to kill or prevent algae. Bacteria and algae are living organisms, organic material and the way to kill them is to oxidise them. Oxidising organic material is the same as if you set fire to it. When you burn something it reacts with oxygen from the air and becomes something else, in the case of bacteria being oxidised it becomes dead.

So to kill bacteria you must add an oxidising chemical to the water and the favourite chemical to do this the world over is chlorine. But if you don’t want to use chlorine you could use a peroxide type chemical. The best known peroxide is hydrogen peroxide, used as rocket fuel and to bleach hair. In swimming pool chemicals they come in the form of persulphates and one of the two sachets in soft & easy contains a persulphate oxidiser that does a very good job of killing bacteria. Persulphate oxidisers are also know as Active Oxygen.

Although peroxides are a good oxidiser for killing bacteria, algae is a different matter. Peroxides are not a strong enough oxidiser to kill algae. Fortunatly there is more than one way to kill algae. One way is to add a chemical called a poly-quat to the water.  The other sachet in Soft & Easy contains a poly-quat  to attack the algae because the peroxide can not do it.

The problem that Soft & Easy has is that if you get an aggressive attack of algae the poly-quat part of it can not cope with the influx of algae and before to long your pool will start to look green. Algae reproduce at an alarming rate and if your pool is green you have live algae and need to kill it straightaway. The only way to kill algae quickly is with a shock dose of unstabilised chlorine. Provided you put enough in, the chlorine will kill the algae in hours and what is not used up in killing will be burnt off by the sun.

So it is not at all uncommon for a pool treated with Soft & Easy to go green from time to time so you will need to have some shock chlorine in reserve to kill off any algae that the copper can not cope with.

Chlorine Shock

Shock (unstabilised) Chlorine

bayrol soft and easy

Bayrol Soft & Easy

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Fi-Clor to change labels on Superfast Shock

Wednesday, April 14th, 2010

Fi-Clor are to make a change to the labeling of their Superfast products to do away with the confusion between the 2.5kg and 4kg tubs.

Both tubs contain the chemical Calcium Hypochlorite but fi-clor have formulated it not only to be 78% strength (normal shock chlorine is 55%) but to rapid dissolve by just scattering on the water. These two improvements have made the product very popular and it is PoolStore’s best selling shock chorine.

However there has been a lot of confusion amongst customers because the label on the 2.5kg tubs says “Superfast Shock” but the 4kg tubs says “Superfast Granules”


Arthur Cox, Technical Sales Manager at Fi-Clor says  “Fi-clor intend renaming all pack sizes of this product as Fi-Clor Superfast Shock Granules.  The names Granules and Shock came about when the product was initially launched in 2000.  This type of product had traditionally been used for shock dosing only, due to its relative insolubility, but following the development of Superfast, we wanted to promote it for regular day to day disinfection.  We therefore felt that naming it as a Shock product would limit the sales potential in this particular application area.  Also, the smaller pack was better suited to giving instructions for shocking a pool without having to actually weigh out product i.e. roughly half the pack (1.25kg) for the average domestic pool.  10 years on from the launch, things have moved on, the market has matured and many pool owners have bought the larger pack for both regular disinfection and shock dosing”

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Are you totally confused about Total Alkalinity?

Wednesday, April 14th, 2010



Total Alakalinity is to swimming pool water what the Liberal Democrats are to british politics. Over shadowed by the other two but important in their own way.

In swimming pool water chemistry the big two are pH and free chlorine level. You have to test for these on a regular basis to be sure your pool is safe and comfortable to swim in. In order to make the water comfortable for bathers eyes and to make the chlorine most effective you must keep the pH between 7.2 and 7.4. Altering the pH is done by adding pH reducer (Dry Acid) or pH increaser (Soda Ash). How easy it is to alter the pH by adding these chemicals is determined by the amount of Total Alkalinity in the water. The ideal range for Total Alkalinity is 80 to 120.

If your Total Alkalinity is too low, when you add pH increaser or pH reducer the pH will alter dramatically with the addition of a small amount of chemical. So your pH will swing from too low to too high or vice versa. If your Total Alkalinity is too high, when you add regular amounts of pH increaser or pH reducer the pH it will have no effect. You have to put much more chemical in before you notice any movement on the pH.

Imagine a traditional weighing scale balanced with equal weights on either side.  You have a 10g weight to add to one side. If  the weight already on each side is 10g then an extra 10g on one side will make a huge difference. This is like having low Total Alkalinity. If the weight on each side was 500g then adding 10g will hardly have any affect at all. This is like having high Total Alkalinity.

Low Alkalinity. Adding 10g makes a big difference

High Alkalinity. Adding 10g makes no difference

So if you are getting wild swings in your pH you need to increase the Total Alkalinity. This is easy, just add some  Alkalinity increaser. See it here on the main website.

Lowering the Total Alkalinity is not quite so easy. You need to add acid (pH reducer) to the water but rather than spreading it evenly through the water you need concentrate it all in one spot. There are many ways to achieve this and we can’t recommend one method over another.  If you know a good way tell us about it. One way is to mix up a bucket of water and dry acid and dump the whole lot in one go in to the deep end. We have tried putting 3kg of dry acid in a washing up bowl, putting it on the steps of the pool and leaving it for a few days. The pool water will gradually disolve the dry acid and bring the Total Alkalinity down. Another way is to take a whole 7kg container, puncture it with nail holes and dangle it in the pool until the Total Alkalinity is about right.


High Total Alkalinity is not a problem from the point of view having safe and comfortable water but lowering it will make life easier for you when adjusting your pH.

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Got Algae? Now you can starve it to death!

Wednesday, March 24th, 2010

Algae is the perennial problem for swimming pool owners.  For years we have struggled to rid it from our swimming pools but it keeps coming back. PoolStore have found a new way to keep it away for good.

 

If your pool is green then it is a little too late for this treatment, you probably need the treatment described here

 

Algae is a living organism whose spores blow in the wind and once in your pool they can multiply very quickly. There have always been two ways to keep algae from forming in your pool.  One is to keep the chlorine level above about 3ppm and the other is to use a traditional algicide. The chlorine will kill the algae on contact but you have to keep a high level ALL the time. Let it drop for a day or two and you could find you have a growth in your pool. Long Life Algicides are a better method than Chlorine because they stay in the water for up to 3 months at a time and kill aglae as it enters the water but if you get a lot of spores blow in it can be overwhelmed.

 

We said earlier that algae is a living organism. Living things need food to eat. Algae eats phosphate for breakfast, lunch and dinner. The more phosphate in water the more algae will love it in there and grow and grow. Phosphate gets in your pool from your tap water.  Some areas have very high phosphate in their water supply. So, if we could remove the phosphate from the water the algae will have no food and therefore die. That is exactly what Starver does.

 

Starver contains a chemical that combines with phosphates and forms a suspension in the water. Filtration and clarifiers will pick this suspension out of the water leaving it phosphate free. No phosphate = No algae.

 

Theoretically one treatment should last forever but unfortunately phosphate finds a way of getting back in your water either from topping from the tap or from rain run off . So you do need to test your water regularly to check your levels and add a bit more starver if necessary. A test kit for phospate levels is included with every bottle of Starver.

 

If you have very high phosphate levels then use Bulk Starver first. This brings the high levels down to more managable levels and then regular Starver can take over.

 

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New Stain Removal System for Swimming Pools

Wednesday, March 24th, 2010

 

PoolStore is pleased to introduce a new system for the removal of stains from the walls and floors of swimming pools.

 

Stains in swimming pools are almost always caused by metals in the source water. The metals come out of solution in one or more place on the shell of the pool and can seem to be impossible to remove by conventional cleaning. The stains are usually brown in colour but can be yellowy or black.  Fibreglass pools seem to be more prone to staining than any other type of pool.

 

The removal of stains is a 2 step process.  First you have to get the stain off the wall by getting the metals out of there and in to the water. Then you have to get the metals out of the water.

 

Start by adding  Multi Stain Remover to the water. This is quite a strong acid and will take the metals out of the walls and in to the water.

 

The second stage is to remove the metals from the water using No More Metal. The metals are held in suspension so they can be filtered out. No More Metal should be added on a regular basis thereafter to keep the level of metals down in the pool water and so prevent the stains from re-forming.

 

Stain removal is not a simple process so read the instructions carefully.  One thing to note is that the first product is very acidic and will alter the pH balance of the pool. When re-balancing the water you must do it gradually over a few days or you will un-do the work that the stain remover did and the stains will re-form.

 

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“Lower chlorine levels will still improve water quality” says new Danish research

Wednesday, March 24th, 2010

From Swimming Pool News, March 2010:

The case for using lower levels of chlorine in swimming pools has been boosted with a new research paper from Denmark.

The paper, which is expected to be available at the Swimming Pool & Spa International Conference in London in March, shows it is possible to achieve significant improvements in the water quality and improved indoor air quality in pools by using a lower content of free chlorine than are currently used in swimming pools. The trial was carried out at the Gladsaxe Sports centre in Denmark.

The trial was carried out by the DHI Group (Danish Hydraulic Institue/ Water Quality Institute), and funded jointly by the Danish Association for Swimming Pool Technology and the Danish Environmental Protection Agency.

Download the Paper

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