Beginner’s Guide to Hot Tub Maintenance (With a Simple Schedule)

Updated September 2026. I’ve rewritten this guide completely. It now has a clear daily-to-yearly maintenance schedule, corrected chemical ranges (the old alkalinity figure was too high), realistic filter cycle times, and tips for DIY tub owners as well as shop-bought spas.

New to hot tubs? Maintenance sounds like a chore, but once you’ve got a routine it’s a few minutes before each soak and maybe half an hour a week. The trick is doing little and often, so small problems never become cloudy, smelly, expensive ones.

This is the routine I’d give any new owner, whether you’ve bought a spa or built your own. For the chemistry detail, I’ve linked through to my deeper guides as we go.

Start by knowing your tub

Before anything else, write these down somewhere you’ll find them (the inside of the control room door is good):

• Water volume in litres and gallons. Every chemical dose depends on it. For a DIY tub, work it out from the internal dimensions and water depth.
• The make and model of the tub, or for a DIY tub, the spa pack, pump, heater and filter. It makes ordering parts or getting help far easier.
• Filter cartridge size: length, diameter and end-cap type.
• Your tap water: is it hard or soft? Hard water means scale, and soft water means you need to add calcium.

The three Cs (plus one)

1. Circulation

Water only gets filtered and sanitised if it’s moving. Most spa packs run automatic filter cycles. The original version of this post said 15–20 minutes twice a day, which is far too short for most tubs. Balboa’s own filter cycle guide uses two three-hour cycles as its example. Check your manual, and if the water isn’t staying clear, add filtration time before you add chemicals.

• Don’t let cycle 1 and cycle 2 overlap, or you lose filtration time.
• Run cycles overnight on a cheaper tariff if you’re on one (Economy 7 or an EV/smart tariff in the UK, time-of-use in the USA).
• On a DIY tub, a small circulation pump running for long periods is quieter and cheaper than running the main jet pump.

2. Cleaning

• Waterline: wipe the scum line weekly with a soft cloth or sponge. Diluted white vinegar is fine on acrylic shells and tiles.
• Skimmer basket: empty it whenever there are leaves in it.
• Filter: this is the big one. I’ve written a full step-by-step in how to clean a hot tub filter cartridge.
• Grit and sand on the floor: see the best way to remove sand from a hot tub.

An old trick is to float a tennis ball to soak up oils. Some people swear by it, but a proper scum-absorbing sponge does the same job and doesn’t shed fuzz into your filter. Better still, ask everyone to shower before getting in. It’s the single biggest thing that keeps water clean.

3. Chemistry

Here are the targets. Where each number comes from, and how to fix it, is in my guide to hot tub chemical levels.

Test	Target
pH	7.2–7.6
Total alkalinity	80–120 ppm
Calcium hardness	150–250 ppm (higher for tiled concrete tubs)
Free chlorine	3–5 ppm
or Bromine	4–6 ppm

A correction: the old version of this post said to keep alkalinity at 125–150 ppm. That’s too high. It makes pH creep up and causes scale and cloudiness. 80–120 ppm is the right range. Always adjust in this order: alkalinity, then pH, then sanitiser. And shock weekly.

Not sure which sanitiser to use? See should I use bromine or chlorine in my hot tub?

4. The cover

A good cover keeps the heat, and your running costs, in, and keeps leaves, kids and pets out. Wipe it over with plain water or a cover cleaner, and apply a UV vinyl protectant a few times a year. The original post suggested a 10% bleach solution. Don’t do that. Cover makers such as The Cover Guy say to avoid bleach, detergents, dish soap and alcohol because they damage the vinyl. Leave the lid open for 20 minutes or so after shocking, so the fumes don’t attack the underside. There’s more in hot tub cover maintenance.

Your hot tub maintenance schedule

When	Jobs
Before each soak	Test sanitiser and pH (strips are fine), check the temperature, and skim out any debris.
2–3 times a week	Test and adjust sanitiser and pH, even if you haven’t used the tub. Top up with water if the level has dropped.
Weekly	Full test (alkalinity too). Shock. Rinse the filter. Wipe the waterline. Empty the skimmer basket. Wipe the cover.
Monthly	Chemically clean the filter. Test calcium hardness (and cyanuric acid if you use dichlor or tablets). Check jets and air controls. Look around the equipment for drips. Press the RCD/GFCI test button as its maker recommends.
Every 3–4 months	Flush the pipes with a line cleaner, then drain, clean and refill. Deep soak the filter. Condition the cover.
Yearly	Replace the filter (every 12–24 months). Inspect the cover for waterlogging, pillows and seals, and the pump and heater for leaks or corrosion. Have the electrics checked if anything looks tired. Before winter, see winterizing your hot tub.

Set phone reminders for the weekly and monthly jobs, or stick a whiteboard in the control room. It doesn’t matter which, as long as it’s the same day each week.

How often should you change the water?

Every three to four months is the usual answer. Jacuzzi gives a handy formula: divide the volume in US gallons by 3, then divide by the average number of bathers per day. That gives you the number of days between changes. For example, a 400-gallon tub used by two people a day works out at about 67 days. Change it sooner if the water is foamy, smelly or won’t stay balanced however much you add.

Your starter kit

• Test strips for daily checks, plus a drop kit or digital tester for accuracy
• Sanitiser (chlorine or bromine) and a floating dispenser if you use tablets
• Shock: non-chlorine (MPS) and/or chlorine granules
• pH increaser and pH decreaser
• Alkalinity increaser
• Calcium hardness increaser (soft-water areas) or stain and scale remover (hard-water areas)
• Filter cleaner, and ideally a spare filter cartridge
• Pipe/line flush for water changes
• Soft cloths, a scum sponge and a skimmer net
• Gloves and eye protection

Common beginner mistakes

• Adding chemicals without testing, or adding several at once. Test, add one, circulate, retest.
• Chasing pH before alkalinity. You’ll go round in circles.
• Thinking a chlorine smell means too much chlorine. It usually means you need to shock.
• Letting the filter go. Most cloudy water starts here.
• Using household cleaners on the shell, filter or cover. They cause foam and damage.
• Leaving the cover off in sunlight. It burns off chlorine and wastes heat.
• Skipping water changes and trying to fix tired water with more chemicals.

Quick troubleshooting

Problem	Where to start
Cloudy water	Filter, then chemistry. See cloudy water in a hot tub.
Foam	Foam in a hot tub
Not heating	Hot tub not heating
FLO or flow error	Clean the filter first, then see hot tub FLO error.
Breaker or RCD tripping	9 reasons your hot tub is tripping the breaker
Water level dropping	How to detect and fix a hot tub leak

Need parts, or planning your own tub?

For filters, pumps, heaters, spa packs and all the bits in between, head to parts4tubs.co.uk in the UK or parts4tubs.com in the USA.

And if you’re reading this before you’ve even got a tub, easy maintenance starts with the design: a skimmer, a decent filter, enough circulation and a control room you can actually get into. That’s all built into my DIY hot tub plans.

FAQs

How often should I test my hot tub water?

Check sanitiser and pH before each soak, and do a proper test at least two or three times a week, even if nobody’s used it. Check alkalinity weekly and calcium hardness monthly.

How long should my hot tub filter cycles run?

Longer than most people think: typically a few hours a day in total, not minutes. Balboa’s own example is two three-hour cycles. If the water isn’t staying clear, add filtration time first.

How often should I drain my hot tub?

Every three to four months for most homes. Or use the formula: volume in US gallons ÷ 3 ÷ average daily bathers = days between changes.

What chemicals do I need for a hot tub as a beginner?

A sanitiser (chlorine or bromine), shock, pH up and down, alkalinity increaser, test strips and filter cleaner. Add calcium increaser or scale remover depending on your water.

Can I use bleach to clean my hot tub cover?

No. Bleach damages the vinyl. Use water or a dedicated cover cleaner, and a UV protectant a few times a year.

What’s the one maintenance job you always forget? Tell me in the comments below. I read them all.

Cheers,
Andi

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Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Fast forward to 2025, I've helped over 1400+ DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi