There’s a time for everything – a time to relax in your hot tub, a time to invite friends for a hot tub party and eventually, a time to purge.
While purging your hot tub doesn’t top the “Fun things to do this weekend list,” it does top the “Glad I did it and I love my hot tub even more” list.
Purging may seem daunting, but it can be easy, especially if you know:
- Why you need to purge
- When to purge
- How to purge
Why purge your hot tub?
Even if your water and sanitizer levels are in the ideal range, your hot tub can develop biofilm over time inside the pipes.
Biofilm is made up of living, reproducing microorganisms, like bacteria. They form communities called biofilms. They make a sticky substance that holds them together. Different bacteria use different methods to form these communities, which depend on the environment and their specific characteristics.
Biofilm can form in the hot tub’s pipes and plumbing system, so you can’t see it.
Many hot tubs have more than 100 feet of pipe – lots of room for biofilm!
If left untouched, biofilm builds up and becomes more and more resistant to any sanitizer.
Blood, sweat and tears
How does biofilm accumulate? In a combination of ways. For example, did you know that the average person brings 100 million bacteria into the hot tub? These bacteria join other living organisms from biofilm to parasites, virus, algae, mold, mildew and spores. Plus, the average hot tub user sweats up to three pints per hour at 102◦F. But that’s not all.
Personal care products – lotion, soap, deodorants, makeup, hair products and perfumes – all dissolve off skin and hair and into the hot tub water.
Nearly microscopic in its early stages, it’s almost impossible to test for and identify biofilm
Biofilm:
- Consumes sanitizer, affects pH and water balance
- Can harbor harmful bacteria colonies
- Causes foam and other water problems
- Reduces pipe diameter in acute cases
Once biofilm forms, it’s difficult to remove even with increased sanitizer or shock treatments.
Now for the good news
Biofilm is removable (in most cases) and preventable. With proper purging, your hot tub and water will be crystal clean and clear for months.
What hot tubs are susceptible to biofilm?
Short answer: all hot tubs, including those that are well-maintained. However, some hot tubs can be more susceptible, including:
- New hot tubs
- Hot tubs used a lot – many times a week by many people – especially if sanitizer levels and filters are not maintained well
- Hot tubs that are not maintained well – for example, with old, used filter cartridges, or incorrect or inconsistent use of sanitizers and no shock routine
- Unused hot tubs – full of water, or even drained (water can be left behind in the pipes)
How do you know when it’s time to purge?
A best practice is to purge your hot tub when you first purchase it.
Hot tubs are “wet tested” at the factory. Wet Testing is when a hot tub is filled with water and tested to make sure there are no leaks.
The hot tubs are drained, but not blown out, meaning that water is in the plumbing for weeks, maybe months before the hot tub is sold and placed in a consumer’s backyard. This allows for plenty of time for biofilm to grow in the pipes.
Purging typically works best when the water is hot – that’s the best time to get all the biofilm and any other build-up out of the pipes and plumbing. Purging every time you drain and refill your hot tub will allow your hot tub to be its most efficient and ensure that your sanitizer works to kill fresh bacteria introduced into the water – not existing or growing bacteria inside the plumbing.
Signs It’s Time to Purge
You should purge your hot tub before draining and refilling whenever possible. It’s especially important if you notice:
- Cloudy hot tub water after cleaning
- Persistent foam
- Bad smells
- Slimy surfaces
- Increased chemical use
- Trouble balancing pH
Many owners ask, “Why is my hot tub dirty after draining?” Often, leftover biofilm inside the plumbing is the reason.
How to Purge a Hot Tub
Follow these main steps – shock, purge and drain. You and your hot tub will be happy in no time:
1. Shock the Water
Start by adding shock to kill bacteria before beginning the purge process.
2. Use a Hot Tub Purge Cleaner
Add a spa purge product, like FROG® Pipe and Jet Cleanser, designed to remove build-up from plumbing lines. Let it circulate according to the manufacturer’s directions — many recommend several hours or overnight. You may notice foam, gunk or discoloration coming from the jets. Don’t fret, that means the purge cleaner is working!
3. Drain and Clean
Once you’ve finished purging, shut off and drain your hot tub according to your owner’s manual. While it drains, clean or replace the filter to help prevent bacteria from carrying over into your fresh water. After the tub is empty, thoroughly clean all interior surfaces — including the waterline, jets, pillows and shell — with FROG® Surface & Cover Cleaner.
4. Rinse and Drain Again
Give the hot tub a final, thorough rinse with a hose, then drain it again. A final rinse will get rid of any residual cleaner, which can cause foam when you refill the hot tub – then you’ll have to drain again. And that’s a draining experience!
Expert Tips:
Use a submersible pump (sump pump), placed in the deepest part of the hot tub. Plug it in and turn it on. Turn it off when the water is drained – if it runs dry the motor can burn. Use a wet/dry vacuum or spa wand to drain any remaining water.
5. Refill
Refill the hot tub with fresh water. Test it for metals and adjust with
FROG® Metal Remover. Then follow the start-up routine your sanitizer product or hot tub retailer recommends to balance your water and then add your sanitizer.
Expert advice
If you use FROG® @ease®, you’ll enjoy the Fresh Mineral Water®∞ experience — Cleaner, Clearer and Softer® water made with up to 75% less chlorine* than traditional systems. Less chlorine means water that’s gentler on your skin, hair, swimsuits and hot tub surfaces, so every soak feels more relaxing and rejuvenating.
FROG @ease achieves this with patented SmartChlor® Technology and FROG Sanitizing Minerals®, which work together to kill bacteria while containing no cyanuric acid, so there’s no CYA build-up. Plus, because the water stays cleaner longer, you can often go beyond the typical three-month drain-and-refill schedule.
Simply replace the FROG Minerals and purge your hot tub every four months to continue enjoying the Fresh Mineral Water∞ experience.
Sources:
Cs.montana.edu A Brief Introduction to Biofilms
ewg.org Survey finds use of personal care products has surged since 2004 – what that means for your health
* Compared to the minimum ANSI recommended chlorine level of 2.0 ppm for a hot tub or swim spa
∞ Cleaner, Clearer and Softer water for pools, hot tubs and swim spas
