Hot Tub Frequently Asked Questions

FAQ’s about Hot Tubs, FAQ’s Swim Spas and FAQ’s about hot tub chemicals.

For all other Hot Tub related questions call our expert advisers on 0800 037 0803.



Q: Do you need planning permission to install a hot tub? A: Usually there is no need for planning permission for domestic temporary/moveable hot tub or swim spa, however, if you live in a conservation area or a listed property, we would advise seeking confirmation from your local authority

Q: What do you need to prepare before installing a hot tub?
A: Access: Hot tubs are relatively easy to install, firstly you should consider access, will you require a hiab or a crane? Can the delivery drivers carry it to your back garden? Location prep: You will need a solid base for your hot tub, we do not recommend placing it on grass due to ground movement which is bad for the shell structure. You will also need power and water supply. If you are planning on sinking your spa then maintenance access needs to be considered. Ultimately hot tubs are easy to plan for.

Q: How to move a hot tub? A: The vast majority of hot tubs are extremely heavy unless you have opted for a portable one. Therefore, we would recommend taking great care when moving your hot tub, yes hot tubs are great for muscle problems, but you do not want it to be the reason your back hurts. Please refer to the manufacturing information when moving as some hot tubs are required to travel flat. Be careful not to place the hot tub on the side where the pumps are contained as this is a weak spot and may damage the shell door. Hire a trailer or flatbed to drive from one address to another, most hot tubs will not fit in a luton or a transit van. Ultimately, we would recommend calling a hot tub company to ensure your property is well looked after. For a list of regulated local companies contact BISHTA.

Q: How long does it take a hot tub to get hot? A: The time it takes for a hot tub t heat up is dependent on the size of spa and the size of its heater. Spa heaters vary between 1Kw and 6Kw and the water volume vary even more. Other factors such as outside temperature and the mains water temperature. For example, a 300-gallon hot tub with a 1.5kw during the summer will take up to 20 hours to heat. However, once your hot tub has reached its optimum temperature it will continue to stay at this temperature until you reduce it, therefore it will only ever be topping up the lost heat. Larger hot tubs in colder temperatures will take longer to reach its temperature but ones with larger heaters will take less time.

Q: How much does a hot tub cost to run? A: Hot tub running costs vary due to the vast differences in hot tub materials, ranging from around £5 a week to £30. To keep your costs down we recommend using a thermal cover, this reduces heat loss significantly and therefore you will spend less on keeping your hot tub warm, why heat your tub only to lose the heat through evaporation. Shell materials and insulation also play a role in keeping your heat in therefore before you choose your perfect tub you should fully investigate what is made of and what insulation it has. A well-insulated and covered hot tub should cost roughly £260 a year to run (based on a 300 gallon hot tub).

Q: Is it more efficient to keep your hot tub hot or heat it up for each use? A: This depends on how often you use your tub, if you are a daily soaker then it is more economical to keep your hot tub on all year round. Your hot tub will lose about 1 degree from 1/2-hour use which will take roughly 20 minutes to recoup. If you are only an occasional soaker then it may be more economical to turn it off but remember you will need to pre-plan use. Please note that if you are not using your hot tub during the winter months, we recommend drained and decommissioned to prevent frost damage.

Q: How long does it take to fill a hot tub? A: Depends on how big your tub is but a 300-gallon spa will take around 1.5 – 2 hours to fully fill using a garden hose pipe.

Q: Can I use hot water to fill my hot tub? A: Yes, you can although this will not save you money and won’t dramatically decrease the heating time.

Spa Maintenance

Q: How do you drain a hot tub? A: Most hot tubs have bottom drains that you use with a hose pipe. However, if you have not got a bottom drain then simply use a submersible pump.

Q: How do you mend hairline cracks in your hot tub? A: As previously mentioned a hard-solid ground is the best way to protect your shell, unfortunately depending on the hot tub, cracks can and will appear. Causes include people sitting on the edge, heavy covers, overloading, and poor manufacturing quality but fear not there are ways to fix these cracks. With fibreglass shells, you can re-fibreglass the area behind the crack. With acrylic shells, you can buy acrylic pellets that you melt with acetone. For more detailed advice and help with cracks please contact a reputable hot tub company.

Q: How do you remove limescale and biofilms from the inside of the pipework? A: Using a spa cleaner such as Hot Tub Flush once a year will keep your hot tub working beautifully and remove limescale and biofilms. Simply add the required amount to your hot tub and run for an hour, once it has finished drain and refill with clean water and run again, drain and refill once more and you are good to go. This is a good time to clean your filter, soak it in cartridge cleaner and then power wash.

Spa Issues

Q: Why will my hot tub not stay hot? A: There are numerous reasons why a hot tub is not heating up such as a faulty heater, circulation pump, broken thermostat or there is not enough water in the hot tub. If your heater can only heat the water when the hot tub is not in use then it could be that you need a larger heater, also many spas turn the heater off when the jet pumps run. Consult with your supplier or seek advice if your heater is not working properly.

Q: I have frozen hot tub pipes, what can I do? A: Sometimes we get caught out by a sudden cold front and the hot tub freezes, unfortunately, this may not be good news as the water expands when frozen and this can cause cracks in the shell and pipework. Wait until the water thaws and test the tub for leaks. During cold months we recommend either keeping the heater on or decommission.

Q: How do you stop hot tub leaks? A: Even the best hot tubs in the world occasionally get leaks, hire a professional who will run a leak test and hopefully quickly and easily identify and fix your leak.

Water Care

Q: What does an Ozone generator do? A: Ozone generators are used to oxidise bacteria and therefore lessen the need for sanitiser. Therefore, if you do not have an ozone then you will need to use more sanitiser such as chlorine or bromine. Please note a UV Ozone system will need to have a new bulb every year! CD ozone systems last longer but generally need changing every 5 years or so.

Q: Can you put soap into a hot tub? A: We know the idea of bubbles in a hot tub may seem like a great idea, however, they will soon overflow and cause mayhem, also the use of detergents builds up scum and bacteria inside pipes. We recommend showering before using a hot tub to reduce the risk of detergent contaminants entering your tub and causing unwanted foam if this happens simply use foam away. If you want to add scents to your hot tub for increased relaxation, we recommend using aromatherapy spa salts.

Q: Do I have to use chemicals in my hot tub? A: Simply, yes, without sanitiser you will get a build-up of bacteria which can be potentially lethal. If you do not like chlorine there are other alternatives such as active oxygen and bromine. However, if you do not want to use any chemicals then you must treat your hot tub as a bath and drain it down after each use.

Q: How do you clean a hot tub filter? A: Overtime, filters will become dirty and clogged, it is important to keep your filters clean to maintain good water quality and to protect the internals of your spa. Remove your filter and place in a bucket of filter cleaner, leave it to soak for at least 24 hours, this will allow the cleaner to break down any oils, grease and other contaminants that are sitting in your filter. Once this is done we recommend hosing your cartridge to remove any leftover cleaner and to rinse the dirt away. If you live in a hard water area your filter may need to use a pressure cleaner to remove any calcium build-up. Depending on how often you use your tub we suggest doing this every 3 months.

Q: How long do you have to wait to get into your hot tub after shock dosing it? A: If you are shocking the spa with Non-Chlorine Shock then allow 10 minutes for it to all mix in and get right in. If you are using Chlorine granules, then you must wait until the Chlorine level has returned to 5 PPM which may take 24 hours.

Q: How often do you have to change hot tub water? A: Most manufacturers suggest changing your water every 3-4 months, but this depends on how often you use your tub. One main reason for this is due chemical build up in TDS (total dissolved solids) after time the sanitiser etc will struggle to dissolve and they will become less effective and you will struggle correct chemical imbalances.

Water Issues

Q: What do you do if your spa water is cloudy? A: Cloudy hot tub water can be the result of two things either your filter is not capturing small dust particles and they are floating in your water, if this is the case we suggest using a flocculant such as spa sparkle, this clumps the dust together which makes it easier for the filter to capture it. Once you have used the spa sparkle it is important to clean your filter so that the dust particles do not make their way back into your water. Alternatively, you have a bacteria build-up which can cause the water to turn murky, if this is the case you will need to shock your hot tub and double the amount of sanitiser, always check levels after 24 hours. If neither of these works then you may need a professional to come in and check your water.

Q: Why is my hot tub green? A: No one wants a green hot tub, we all know that is not a good colour for any water especially one you are planning on sitting in. If your water has gone green, it means you have active bacteria and algae. Firstly, do not use your spa if the water is green. Secondly you will need to empty the tub and thoroughly clean it with a strong sanitiser such as chlorine, we would also recommend doing a full flush. Scrub all surfaces and remove any trace of the green. Fill, shock dose and away you go.

Hot Tub FAQ’S