How to Change a Hot Tub Filter

Your hot tub filter is one of the hardest-working components in the whole system. It catches debris, dead skin cells, oils and particles before they reach the pump and heater. A blocked or degraded filter is one of the most common causes of water quality problems, reduced jet pressure and heating faults.

How often should you change your filter?

As a general rule:

• Rinse your filter every 1–2 weeks with a hosepipe (not a pressure washer)
• Deep clean with a filter cleaning solution every 4–6 weeks
• Replace the filter cartridge every 12 months, or sooner if it shows signs of damage

Signs your filter needs replacing

• Permanently cloudy water even with correct chemical levels
• Reduced water flow or jet pressure
• Filter media is discoloured, frayed, or the pleats won't open out properly
• FLO error codes on your control panel
• Filter has been in use for over 12 months

What you'll need

• Replacement filter cartridge (see below for sizing)
• Hosepipe
• Filter cleaning solution (if reusing)
• A bucket

Step-by-step: changing your hot tub filter

1. Switch off your hot tub — turn off jets and set to standby mode. You don't need to drain it.
2. Locate the filter housing — usually inside the tub near the skimmer basket, or in a dedicated filter compartment on the cabinet. Check your manual if unsure.
3. Remove the old filter — unscrew the filter lid (usually anti-clockwise) and lift the cartridge straight out. It may be wet and heavy.
4. Rinse the housing — give the filter bay a rinse with clean water to remove any debris left behind.
5. Insert the new filter — lower it straight in, making sure it seats correctly. Don't force it.
6. Replace the lid — screw it back down firmly by hand. Don't overtighten.
7. Restart the tub — switch back on and check for normal flow through the jets within a few minutes.

Finding the right replacement filter

Filter sizes are not universal. You need to match by diameter and length, and sometimes thread type. The part number is usually printed on the end cap of your existing filter. Common brands include Pleatco, Darlly and Unicel.

If you're unsure, bring the old filter to us or send a photo — we can identify the correct replacement and supply it.

Can we do this for you?

Filter inspection, cleaning and replacement is included in all our maintenance packages. If you'd rather we just handle it, get in touch.