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    Hot Tub Chemistry Guide

    Although the word “Chemistry” might fill some people with dread, it’s really not as daunting as it sounds to maintain the correct balance of chemicals in your tub or swim spa. Incorrect use of chemicals in your tub can cause various, potentially costly issues as well as serious, even life threatening illnesses .

    There is often incorrect information regarding dosing and maintenance on the internet so it is crucial that you get the information from a reputable source.Here are a few do’s and don’ts.

    • Never use household chemicals in your tub such as washing up liquid, bleach or cleaning sprays. Doing this can void the warranty.
    • Do not use chemicals designed for swimming pools.
    • Do not use oils or bubble bath intended for use in a bath as these will alter the chemical balance. Our range of scented salts designed for hot tub use can be found here
    • Replace your filters every 5-6 months with genuine filters. It’s advisable to have a spare set and rotate fortnightly so that your filter has time dry thoroughly.
    • Shower before entering the tub is advisable as perfumes and other toiletries can affect the chemical balance.
    • We recommend Changing the water in your hot tub every 3-4 months.

    The most important piece of equipment you will need is something to test the water. This can range from the handy dipsticks to more complex devices that can even be bluetooth connected to your phone. See our full range here


    These are the main levels that you should be monitoring,

    • PH levels – These should be between 7.2 and 7.6
    • Alkalinity – Should be between 80 – 120
    • Sanitizer levels – Chlorine 1.5 – 3.0 or Bromine 3.0 – 5.0
    Here is a quick visual guide

    What does each chemical do?

    Sanitisers –

    • Chlorine – The same way  bleach to used to kill bacteria, fungus, and viruses in your kitchen and bathroom, chlorine does all that for your hot tub water. The chlorine smell  is a result of the chlorine killing contaminants by oxidizing.
    • Bromine -Bromine has a few advantages over chlorine. Not only does it have a lower pH than chlorine, making it a little easier to keep the water balanced, it also lasts longer and it’s gentler on your skin.  Although it lasts longer than chlorine, it also works slower, which means contaminants are in the water longer before they are destroyed. bromine ionizes contaminants, breaking them apart at the molecular level, which means it does not have the strong odour often associated with chlorine.
    Alkalinity Reducer or Increaser –
    Also know as TA, You will need to adjust the alkalinity before trying to balance the pH level. Alkalinity acts as a pH buffer, keeping it from drastically changing.
    PH Plus and Minus – 
    The pH level being too high is one of the main causes of cloudy hot tub water. If the level goes above 7.6, and you start to see problems, try using a pH decreaser to brings things back down to normal.  pH Plus is used when the water is too acidic.
    Foam Away – 
    Used to filter away pollutants like perfumes or lotions.
    Scale Away – 
    Used to prevent scaling and calcium from solidifying in your tub, especially the pipes in hard water areas.
    Hardness Increaser –
    Used to increase the water hardness in areas that have soft water issues.
    Tub shock – 
    Hot tub shock is an oxidising water treatment that quickly raises the level of sanitisation. This should be done weekly as part of your hot tub maintenance, if you’ve not used your hot tub for a while or have used it excessively
    There are also plenty of cleaning products on our website that are specifically designed for use in tubs. To view our full range please see here  or if you are still feeling nervous about the chemistry aspect of your tub then please contact a member of our team 0115 9442211
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