Have you ever wondered why hot tub chemicals range in price so much? If it’s cheap there’s usually a reason why. It all goes back to that old expression “you get what you pay for”.
Quality chemicals have a higher concentration of beneficial product. They are made with less fillers and water. Lesser qualities are cheaper, but you will use more, and you will have to attend to your tub more often as they won’t be doing the job as well. They may also have perfumes and other additives that aren’t necessary. A quality product does not need perfume because if used right it will work, and the odor of your tub won’t need masking.
Make sure that the products you use are designed for hot tubs, and not pools. A hot tub requires similar but different products because of the temperature difference and amount of water. Typically pool chemicals have different stabilizing ingredients that are not helpful in getting spa water balanced. These ingredients can alter your ph to a point where your hot tub’s components are being damaged. If you have been using lower grade chemicals the most obvious signs of damage are as follows:
Rubber damage – O-rings, pump shaft seals, jet seals, light seals,
Surface Damage – Big white ring at water level.
Cosmetic damage – Handles and dials bleached, control panel overlay fluffing on edges, and stainless steel trim rusting.
Human Damage – skin irritation, skin bleaching and burning, rashes, discoloration of dyed hair.
Introducing ozone into the water will kill bacteria. It improves the smell, feel and clarity of the water and helps clear scum and oils.
Ozone is generated by either passing air over a powerful ultraviolet light or by passing it through a corona discharge (a sort of lightning storm in a box). The high energies convert ordinary oxygen into ozone, a very reactive molecule that attacks organic material.
If your tub is equipped with an ozone system your chemical needs will be reduced, but not gone. You still need to sanitize, balance the PH and Alkalinity, and shock regularly.
Why Pool and Spa Water must be balanced
Serious- even life threatening- illnesses can be spread by water that is not properly maintained. Your expensive pool or spa and all of its equipment are under threat from unbalanced water. Also the water just gets plain yucky! By that highly technical word, I mean, algae, slime and unpleasant smells become an unwelcome part of your swimming experience.
Things to Monitor Regularly
Keeping water in a swimming pool or spa healthy and balanced is a question of understanding what is in the water, how the various chemicals can be measured and what needs to be added to get things to the right level.
There are five important properties of pool spa and hot tub water that need to be routinely monitored: the sanitizer, total alkalinity, pH level, hardness, and total dissolved solids. With the right chemical kit or test strips these can be measured quickly and easily.
The difficult part comes when you adjust one of the components and find that it has affected other components in a way that you don't want. This is why people talk about 'balancing the chemicals' in a spa or hot tub. Get the proportion of chemicals right and the water is balanced, healthy, safe and fresh. This needs a little practice but is pretty simple once you grasp the essential facts.
First off, it's worth looking at the kind of chemicals used in pool, spas and hot tubs and what their job is.
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Sanitizers
Sanitizers do what they say they do. They kill bacteria and anything else in your pool or spa that might threaten your health. They also help to stop algae growth.
Chlorine Sanitizer
The most common and cheapest sanitizer is chlorine. When the chlorine comes into contact with any organic material like bacteria or dead skin flakes the chlorine attacks the organic material and breaks it down (technically, it oxidizes it). The common salt- Na Cl- remains behind in the water.
In storage, it needs to be kept cool and away from sunlight.
Dichlor (Sodium Dichloro-s-Triazinetrione)
This is a solid product with about 60 per cent available chlorine. It is weakly acidic. This is a popular choice for home use, as it is stable, doesn't affect water pH too much and is safer than the Trichlor described below.
Trichlor (Trichloro-Triazinetrione)
This product usually comes as tablets or sometimes as granules. It is slow dissolving which can be an advantage if you want to keep water fresh while you are away. It is often used in automatic sanitizer delivery systems.
It has 90 per cent available chlorine and is the most expensive of the chlorine sanitizing products. It is also the most highly acidic and pH will need to be adjusted whenever it is used.
For professional spa and pool technicians, this is the chemical of choice for tackling serious algal problems. It also has the advantage of being very stable so it can be kept for long periods without deteriorating.
Safe Handling of Chlorine
All strong chlorine solutions will attack skin and natural clothing (e.g. cotton or wool) and should be treated with respect. Gloves and eye protection are recommended for handling very strong chlorine solutions. Trichlor is a lung irritant.
Chloramines, Free Chlorine and Total Chlorine Load
Chloramines are formed when chlorine reacts with ammonia from sweat or urine in the water. These are the chemicals that give the strong smell and stinging eyes associated with chlorine use. If water is well maintained, chlorine sanitizer will cause little irritation.
Chloramines don't kill bacteria so ammonia is said to 'tie up' chlorine. Only the free chlorine is able to act as a sanitizer.
To manage a hot tub or spa successfully it is important to know both the free chlorine levels and total chlorine levels. High total chlorine indicates the need for a chlorine 'shock' (see below).Test strips from your local or online supplier allow you to measure free and total chlorine quickly and easily.
Different Folks, Different Names
One area of confusion in spa and hot tub maintenance is that people use a lot of different names when talking about the same thing. When it comes to chlorine sanitizer, this is especially so.
Free Chlorine=Available Chlorine=Residual Chlorine
Total Chlorine=Chlorine Load= Combined Chlorine.
There are only ever two chlorine measurements to worry about in pool or spa water. Just pick a name for each and stick to it!
Chlorine Shock (or Super Chlorination)
Spas and hot hubs need a regular 'shock' treatment to clear out organic material. Chlorine shock is OK to use where either chlorine or bromine is the sanitizer.
A chlorine shock needs to be applied at anything from weekly to monthly intervals depending mostly on bather load. Check packaging of your chlorine product for doses. 10 ppm of free chlorine is usually strong enough as chlorine shock. Non-chemical sanitizer systems like ozone generators and ionizers reduce the need for shocking.
Essentially, a shock is needed whenever there are any obvious problems with water quality such as cloudiness, smell or algae and is a good idea after any heavy use of the pool, spa or hot tub.
After a chlorine shock, keep people out of the water for at least 24 hours and test the water to make sure it has returned to less than 5 ppm of chlorine before giving the all clear to users
Non-Chlorine Sanitizers
Bromine
This is used as an alternative to chlorine when people don't like the odors produced by chlorine. It is also more stable than chlorine at the high temperatures found in hot spas. It can be applied in granular or stick form. A small amount of chlorine is often used as a catalyst (ie to activate the bromine) but non-chlorine catalysts are also available.
One advantage of bromine sanitizer is that when the bromine is 'tied up' by organic contaminants or ammonia from sweat etc, it can be easily revived. Shocking once a week or so (depending on the number of bathers) with chlorine or non-chlorine shock will bring free bromine levels up, without necessarily having to add more bromine.
The ideal range for bromine is 2.0 to 4.0 ppm.
If you overdose with bromine, the levels will fall fairly slowly. Supply shops sell chlorine and bromine neutralizers if you need a quick reduction.
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Problems with Algae
Inadequate filtration or not using enough sanitizer can lead to problems with algae. If you have problems with algae check this page.
Other Important Water Properties
Acids and Alkalis
pH is the scale used to measure how acid or alkaline water is. 7 is neutral. Anything less than 7 is acidic, anything above 7 is alkaline. Spas and swimming pools need to be kept between 7.2 and 7.8.
If spa or pool water becomes too acidic, the water will attack and corrode metal fittings, sometimes leading to water discoloration. If water becomes too alkaline it encourages scale to form on the pool or spa sides and equipment. Heater failure is a common result.
PH also has health implications because it has an impact on how well sanitizers work.
Acid- either in liquid or granular form-is used to adjust pH. Test kits for pH are available from spa and pool supplies stores. Adding too much acid means you will need to correct with alkaline products like 'ph up'.
pH anchors can be used to lock in pH levels but these affect your ability to adjust water hardness.
If the pool or spa has plastered or tiled walls, alkaline lime in the plaster or grout is constantly dissolving so more monitoring of pH may be needed.
Total Alkalinity
This is a measure of all the chemicals in the water that have a potential to be alkaline. This needs to be measured and the alkaline materials (like dissolved lime) need to be neutralized before pH is adjusted. This will save a lot of sanitizer and acid use in the long run. Alkali neutralizers can be bought from any good spa or pool supplier. Excess alkalinity will contribute to lime scale deposition which in the worst cases blocks jets and pipes. Total alkalinity outside of the normal range can make pH fluctuate wildly.
Water Hardness
Water hardness can affect spas in two ways. If the water is too soft it can slowly dissolve metal components in pipework and pumps. In plaster-walled or tiled pools and spas it will dissolve cement and grout. Water that is very hard will deposit lime scale, clogging pipes, jets and filters. If left unchecked lime scale can cause failure of pumps and water heaters.
Water hardness can be measured with test strips and adjusted with products like Calcium or Scale and Stain Control (decreases water hardness). If you use a pH anchor to maintain a constant pH do not use these products, reduce water hardness by draining the water and refilling.
If your tap water is too hard then you may have to invest in a water softening system or water softening agents.