We’ve collected together every question we’ve ever been asked about hot tubs and put them into one article. Here’s everything you need to know about hot tubs.

All the most popular FAQs for hot tubs

Can I put soap into a hot tub? 

Please don’t! It might seem like a fun idea but it’ll bubble like mad, the bubbles will escape all over the garden, and once it starts it’s hard to stop the foam – it just keeps on foaming. Also, using detergents builds up scum and bacteria inside the water pipes. To add lovely scents to a hot tub, use special aromatherapy spa salts.

Do you need planning permission for a hot tub?  

Unless you live in an area of outstanding natural beauty , your house is listed or you’re in a conservation area, there’s no planning permission for hot tubs. If in doubt ask the council.

Is it hard to install a hot tub?

They’re easy enough to install once you have the right surface to put it on. The most important thing is a hard, solid base because water is extremely heavy. You’ll also need easy access to electricity and water. And think about access as well – it’s no fun if people can’t get in and out because there’s not enough room or a wall in the way!

Do I have to use chemicals in a hot tub?

Yes. Otherwise the water will go green within a few days, filled up with algae like any other body of water left outdoors. If you don’t like chlorine you can use active oxygen and bromine instead. If you want to avoid chemicals altogether you’ll have to drain and clean it every time you use it, just like you do with the bath indoors.

 How to clean a hot tub filter?

Easy! Take the dirty, clogged filter out and put it in a bucket of filter cleaner for at least 24 hours. Also hose down the filter cartridge to get rid of dirt and residues of cleaning fluid. If you live in a hard water area you might need to use a pressure washer to get the limescale off. Do it every 3 months or so for a safe, clean, healthy hot tub.

I have shock-dosed my hot tub – now what?

How long to wait to use a hot tub after shock-dosing it? A non-chlorine shock treatment needs ten minutes to mix into the water, then you’re good to go. Chlorine granules take longer – you’ll have to wait until the water’s pH goes back to 5 parts per million, which can take 24 hours.

How often to change hot tub water?

Go for every 3-4 months, more frequently if you use the tub a lot and there’s more chemicals built up in as total dissolved solids. Leave it any longer and you might have problems getting the right chemical balance.

What if hot tub water goes cloudy?

Perhaps the filter isn’t doing its work, leaving you with a load of tiny dust particles floating in the water, in which case you need a flocculant to clump the particles together so the filter cab catch them.  Clean the filter afterwards or the dust will just end up back in the water. It could also be a build up of bacteria, which means a shock treatment is in order. Double the amount of sanitizer and check back in 24 hours to see if the water’s clear. If neither of these work, get a pool expert in to help you.

If the water’s green it means  it’s full of active bacteria and algae, basically algae soup. Nasty! Don’t use it, , scrub it using a powerful sanitizer like chlorine and do a full flush to get rid of all the green.

How much does running a hot tub cost?

It depends on the weather, the cost of electricity, and your hot tub’s efficiency. But you’ll probably be surprised at how little they cost to run. Buy a fitted hot tub cover to keep the heat in and the heating costs lower.

I want to move house with my hot tub – how? 

Hot tubs are extremely heavy unless they’re portable models. Check what the manufacturer says first, and follow their recommendations.  Never lie it down on the side where the pumps are, it’s a weak spot and you can damage or break the door. Because they don’t usually fit on a Luton van or Transit, you’ll need to use a trailer or flatbed truck to move it by road.

How long does it take to fill up and heat a hot tub?

Spa heaters vary between 1Kw and 6Kw. It heats up faster in hot weather. An average size tub and decent water pressure takes 1-2 hours to fill, something you’ll only need to do every few months. Initial heating takes as long as 24 hours but after that it’s a matter of just topping the heat up, taking about half an hour. As a general rule it takes 1.5 to 2 hours to fill a 300 gallon model, so you can use that as a rough guide.

Can you use hot water to fill a hot tub?

Yes, although it won’t save you much time or money. It’s six of one, half a dozen of the other.

How long can you stay in a hot tub?

As long as you like unless you’re pregnant or have a health problem like heart disease, diabetes or high blood pressure. If that’s you, ask your GP first.

 What water temperature for a hot tub?

In summer most people go for 37C, roughly body temperature. In winter you can set it as warm as you like, but most hot tubs won’t go over 42C for health and safety.

Tell me about horsepower and jets – Do I need big ones?

The water volume output is a lot more important than the horsepower or jets.

Do I keep the hot tub on or off?

It depends how often you use it. Daily use makes keeping it permanently on more economical. It’ll lose approximately 1 degree per half hour of use, taking around 20 minutes to heat back up. If you’re not using it often it’s probably best to turn it off in between sessions.

About hot tub maintenance

Always follow the manufacturer’s guidelines to the letter when adding chemicals like bromine and chlorine, and at all other times. Look at the water frequently, drain the tub every three months, keep it covered and make sure the cover is in good condition. Make sure the filters are working. They’re the basics.

How to drain a hot tub?

There’ll probably be a bottom drain to put a hosepipe in. Otherwise you can use an underwater pump.

Why does my hot tub keep going cold?

Check for a broken or faulty heater, circulation pump, or broken thermostat. Make sure there’s enough water in the hot tub. Do you need a bigger heater? Does your hot tub automatically turn the heating off when the jets are running? If it isn’t any of these common problems, ask an expert.

What if my hot tub pipes freeze?

Freezing  can mean cracks in the shell and pipes. You won’t know until the ice has thawed. Either decommission the tub in winter or keep the heater on to prevent ice.

What if the hot tub leaks?

A professional will do a leak test for you. If it’s not major they should be able to repair it. Cracks can appear from heavy people sitting on the edge, heavy covers, and overloading, but fibreglass shells can be mended using more fibreglass behind the crack. You can also mend acrylic shells, using special acrylic pellets that melt with acetone. You’ll probably need an expert to do it for you.

Is hot tubbing good for health?

Relaxation is good for you – it cuts stress, eases sore muscles, helps with arthritis, increases blood flow, relieves swelling from injuries and soothes chronic pain. It can even help you sleep better.

What does a hot tub ozone generator do?

Ozone generators oxidise bacteria so you can use less sanitizer. If you fit a UV Ozone system you’ll need to change the bulb annually. CD ozone systems last longer, needing a change every 5 years.

Reassured? Informed? Great stuff. Now go check out our hot tub collection!