Top 10 Hot Tub Maintenance Mistakes to Avoid
Max PiggottA hot tub needs regular care to stay in good condition, but the routine doesn't have to be complicated. Most problems, from cloudy water to broken parts and expensive repairs, come from a handful of common mistakes.
Here are the top 10 hot tub maintenance mistakes and how to avoid them.
1. Ignoring water chemistry
If you don't test and balance the water regularly, you can end up with cloudy water, scale or skin irritation.
Tip: Test at least 2–3 times a week with 3-in-1 test strips and adjust pH, alkalinity and sanitiser as needed.
2. Using the wrong chemicals
Household cleaners, pool chemicals and cheap substitutes can damage the acrylic shell, the pumps and the jets.
Tip: Always use hot tub-specific chemicals and follow the dosing instructions.
3. Overusing sanitiser
More sanitiser doesn't mean cleaner water. Too much can damage components and irritate skin.
Tip: Stick to the recommended levels and only shock when needed. Leave the lid open for half an hour after adding chemicals to protect the underside of the cover from chlorine damage.
4. Neglecting the filter
The filter does most of the work of keeping the water clean. Neglect it and you get cloudy water and extra strain on the pump.
Tip: Rinse the filter weekly, deep clean it monthly with a hot tub filter cleaner and replace it every six months (up to twelve with careful upkeep). Our guide on how often to clean your hot tub filter explains the routine in more detail.
5. Not showering first
Oils, lotions, make-up and even washing powder residue on swimwear can clog filters and upset the water balance.
Tip: Ask everyone to rinse off before getting in.
6. Leaving the water too long
Keeping the same water for months lets bacteria, scale and foam build up.
Tip: Drain and refill every 3–4 months, or more often with heavy use. When it's time, follow our guide to operating the drain valve to empty your spa.
7. Ignoring the cover
A dirty or damaged cover lets in debris, raises energy costs and affects water quality.
Tip: Clean the cover monthly and replace it if it becomes waterlogged or cracked.
8. Running the jets with too little water
If the water level drops too low, running the jets can burn out the pump.
Tip: Always check the water level before switching the jets on.
9. Skipping regular checks
Small problems such as leaks, loose fittings or worn parts can quickly become expensive repairs.
Tip: Give the spa a quick check each week and book a professional service once a year.
10. Forgetting about winter
In freezing weather, a spa that isn't winterised properly can suffer frozen, cracked pipes.
Tip: If you won't be using the spa over winter, follow the manufacturer's winterisation guide or have an engineer do it.
Already made one of these mistakes? How to fix it
Most of these mistakes can be put right in an afternoon. Here is what to do for each one if the damage is already showing.
| Mistake | What you will notice | How to put it right |
|---|---|---|
| 1. Ignoring water chemistry | Cloudy or dull water, scale on the waterline, itchy skin | Test, then correct total alkalinity first, pH second and sanitiser last. Re-test after the pump has run for a while. |
| 2. Wrong chemicals | Foam, a strong smell, marks on the shell | Stop using the product, flush the pipework, drain, clean the shell and refill with fresh water before using spa-specific chemicals. |
| 3. Too much sanitiser | Harsh smell, sore eyes, bleached patches on the underside of the cover | Leave the cover off and the jets running to let the level fall, then retest. Do not add anything else until it is back in range. |
| 4. Neglected filter | Weak jets, cloudy water, slow heating | Soak the cartridge overnight in filter cleaner and let it dry. If the pleats are matted or torn, replace it. |
| 5. No shower first | Foam and a greasy line at the waterline | Use a defoamer as a short-term fix, wipe the waterline, and shock the water to break down oils. |
| 6. Water left too long | Water that will not balance, persistent foam or smell | Flush the pipework, drain, clean and refill. No chemical will rescue water that is past its life. |
| 7. Neglected cover | Heavy cover, mould on the underside, higher heating bills | Clean both sides with mild soap and water. A waterlogged or cracked cover needs replacing. |
| 8. Low water level | Surging jets, pump noise, heater cutting out | Switch off, top up to about 25mm above the waterline, then restart. If the pump will not move water, clear the airlock. |
| 9. Skipped checks | Damp in the cabinet, drips under the spa | Switch off, remove the access panel and look for the source. Tighten loose unions by hand and call an engineer for anything else. |
| 10. Forgetting about winter | Error messages, cracked fittings after a freeze | Keep the spa running and covered in cold weather. If it has frozen, switch off and contact a service engineer before restarting. |
Water balance targets to aim for
Mistakes 1 to 3 all come down to not knowing what the readings should be. Keep these numbers somewhere you will see them, such as inside the lid of your chemical box.
| Reading | Target | If it is low | If it is high |
|---|---|---|---|
| Total alkalinity | 80 to 120 ppm | Alkalinity Booster, added slowly | Correct gradually with pH Down, re-testing as you go |
| pH | 7.2 to 7.6 | pH Up | pH Down |
| Chlorine | 1.0 to 1.5 ppm | Chlorine granules | Leave the cover off and let it fall naturally |
Always adjust alkalinity before pH, because alkalinity acts as a buffer that holds pH steady. If you correct pH first, it usually drifts straight back out. If your water temperature is below 20°C, dissolve chlorine granules in a plastic container of water before adding them.
A maintenance schedule that prevents all ten
The simplest way to avoid every mistake on this list is to give each job a fixed slot. Print this out or copy it into the maintenance log mentioned below.
| When | Job | Prevents mistake |
|---|---|---|
| Before every soak | Check the water level and shower | 5 and 8 |
| 2 to 3 times a week | Test and adjust alkalinity, pH and sanitiser | 1 and 3 |
| Weekly | Rinse the filter and look around the cabinet for drips | 4 and 9 |
| Monthly | Deep clean the filter and clean the cover inside and out | 4 and 7 |
| Every 3 to 4 months | Flush the pipework, drain, clean and refill | 6 |
| Every 6 to 12 months | Replace the filter cartridge | 4 |
| Every autumn | Check the cover, refill if due and decide whether to keep running or winterise | 7 and 10 |
| Once a year | Professional service | 9 |
What to keep in your maintenance kit
Many of these mistakes happen because the right product was not to hand. A basic kit covers almost everything:
- Test strips for alkalinity, pH and sanitiser
- Sanitiser, such as chlorine granules or bromine tablets
- pH Up, pH Down and an alkalinity booster
- A non-chlorine shock for after heavy use
- Filter cleaner and a spare filter cartridge
- A defoamer for occasional foam
- A pipework cleaner for each water change
The Complete Hot Tub & Spa Chemical Kit covers most of the chemicals in one box. If you would rather have a professional look after the annual service, see our hot tub servicing options.
Hot tub maintenance FAQ
How much time does hot tub maintenance take each week?
For most owners, around 10 to 15 minutes a week covers testing, balancing and a filter rinse. The bigger jobs, such as a water change, come round every few months.
What is the most common hot tub maintenance mistake?
Neglecting the filter. It affects water clarity, jet strength and heating all at once, and it is the easiest one to fix.
Can I use pool chemicals in my hot tub?
It is best not to. Hot tubs hold far less water at a much higher temperature, so pool products and doses are not designed for them. Use spa-specific chemicals and follow the dosing instructions.
Should I switch my hot tub off when I am not using it?
Generally no, particularly in cold weather. A running spa circulates and filters the water and protects the pipework from freezing. If you plan to stop using it for a long period, drain and winterise it properly.
Do I need an annual service?
It is worth it. An engineer can spot worn seals, loose unions and early pump problems before they turn into a breakdown, which is mistake 9 on this list.
Final thoughts
Most hot tub problems come from simple oversights. Avoid these mistakes and stick to a regular routine, and your water will stay clear, the equipment will run smoothly and your spa will last for years.
Tip: Keep a simple maintenance log. Recording water tests, filter cleans and refills takes the guesswork out, helps you spot patterns early (such as pH that keeps drifting) and helps your spa last longer.
Keep your water clear
Find the right filters and water-care chemicals, or book a service.