Hot Tub Flush

Clear biofilm out of your hot tub pipework before a water change. One 200 ml dose dissolves the slime layer that shields bacteria from your sanitiser and keeps demand stubbornly high.

• Works into and dissolves the biofilm inside pipework and jets.
• Releases trapped body oils, lotions and dead skin.
• Gives the fresh fill its sanitiser efficiency back.
• Removes the cause of cloudy water that keeps returning days after a refill.
• Helps tubs pass routine bacterial swab tests.

Sizes and prices

Available in 1L, 2.5L, 5L, 10L, 20L, 25L.

• 1L: £8.99
• 2.5L: £14.93
• 5L: £24.83
• 10L: £44.63
• 20L: £84.24
• 25L: £104.04

How to use

1. Take the cartridge filter out and set it aside; do not refit until after the refill.
2. Pour 200 ml of Hot Tub Flush per 1500 L straight into the tub.
3. Switch the jets to high and run them uncovered for 30 minutes.
4. Turn the jets off and leave it to soak for 8-12 hours, ideally overnight.
5. Run the jets again for 10 minutes, then drain the tub completely.
6. Wipe the shell, hose out the empty tub, refit a clean filter and refill with fresh water.

Frequently asked questions

How often should I flush the pipework?

At every quarterly water change, or after any heavy bather event.

Do I have to take the filter out?

Yes. Biofilm release and surfactants would ruin it. Set it aside and refit a clean one after the refill.

How long should the soak be?

8-12 hours overnight is standard. Allow up to 24 hours for tubs that have not been flushed in years.

How many flushes does 1 L give?

Five flushes of a 1500 L tub at 200 ml each.

Is it safe for inflatable hot tubs?

Yes. Used as directed, the flush is safe for vinyl, acrylic and inflatable surfaces.

Will it damage my pump or heater?

No. The active dilution sits well below the thresholds for pump impellers, seals or heater elements.

What is biofilm chemically?

A polysaccharide gel that bacteria produce to anchor themselves to surfaces and shelter from sanitiser.

Why can sanitiser not clear biofilm?

Free chlorine and bromine react at the surface and do not get into the gel matrix. It takes specific surfactant chemistry to break the matrix down.

Does it raise total dissolved solids?

Briefly, but the whole flush is drained away, so the new fill starts at TDS zero.

Loads of foam during the flush?

That is expected. Ease off the jet speed; the foam settles once the jets stop. Drain after the soak.

Smell still there after the refill?

Drain a second time and re-flush at the same dose; very neglected tubs sometimes take two cycles.

Sanitiser demand still high after refill?

Replace the filter cartridge and shock the new fill; an old filter or unwashed shell carries the biofilm forward.

Hot tub flush or filter cleaner?

Flush clears pipework biofilm before a water change. Filter cleaner cleans the filter element. Use both at every water change.

Hot tub flush or household bleach?

Bleach reacts at the surface and rarely gets into biofilm. The flush uses surfactants and chelators that strip the matrix out.