Nothing will put you off a comfortable soak in a hot tub; quite like removing the cover to find staining all over the place! It might not be the most common mess, but it’s undoubtedly one of the most shocking.
It can be difficult to determine why these yellow stains appear, so our team has deeply dived into the causes and cures for this tricky problem.
With over ten years of experience as the top spa cleaning guide, it’s time to put our knowledge to the test!
How to get yellow stains out of an inflatable hot tub?
Here’s what you can do to fix it!
Inflatable Hot Tub Stained Yellow
The hot tub water chemistry is off.
There are a few reasons your hot tub may turn yellow, though the most likely cause is a wonky chemical balance. Your hot tub’s water chemistry is delicate, so it’s easily thrown off by the oils, sweat and other contaminants we bring with us when we bathe.
Not cleaning your hot tub filters regularly.
These body oils and other bits of residue build up over time and can form a yellowish film in water that’s not been adequately sanitised and filtered, which is why it’s super important to check your pH balance and learn how to clean spa filters correctly so you’d don’t encounter grime and slime in your spa.
Too much metal
Another likely cause of colour distortion or stain in your spa tub is the presence of minerals like iron in your water supply. These tiny particles may not be visible to the naked eye, but they can leach out into the water, forming yellow stains on the linings of your hot tub.
If you have a hard water supply or use well water to fill your hot tub, we recommend filtering the water before using it to fill your spa!
What Causes the Yellow Stain in a Hot Tub?
If you notice hot tub yellow stains littering the linings of your inflatable hot tub, this could be down to unbalanced chemicals, the contaminants in mineral-heavy water, or the issue may be hidden rust stains if your spa tub contains metal components in contact with the water.
Some inflatable hot tubs have metal housings around the massage jets, valves and other fixings under the water line, which can begin to rust, resulting in yellow stains around the areas where flakes of oxidised metal have been in contact.
Another reason portable spas develop yellow stains is their primary construction material, PVC. Although PVC is an incredibly durable, cost-effective and versatile material, it’s known to turn a different colour over time, especially when exposed to UV, oils and solvents.
To best protect PVC, you should keep your hot tub covered to limit its UV exposure, have your bathers shower to reduce the presence of oils or lotions in the water, and refrain from using solvent or oil-based solutions when cleaning the material.
How To Remove Yellow Stains From a Hot Tub
So, now we’ve worked out the cause of that unsightly mark, below we have three simple ways to get yellow stains out of the hot tub.
I’ve had yellow stains on Lay Z Spa models before and these solutions work well.
1- Powdered Bromine or Chlorine sanitiser
Essentially, the idea here is to perform a heavy shock treatment with whichever sanitiser you usually use. Whether it’s chlorine or bromine, you’ll need to add twice as much as your average shock dose to sanitise and bleach the source where the yellow stains are.
Add powdered sanitiser to the water and run your pump for a few hours; this will give the chemicals time to wash every surface, killing the build-up of bacteria, algae, stains and mould that builds up and turns your hot tub a nasty colour! There are a number of things and methods you can use, but we find these cleaners to be some of the most effective.
Depending on the severity of your hot tub stains, you may need to repeat this process a couple of times. Just make sure to wear gloves and eye protection when handling sanitisers, and thoroughly drain, clean and rinse your jacuzzi tub before refilling it!
2- Use a magic eraser
Popping a magic eraser in your pool store can prove super handy, especially when you need to remove yellow stains and marks from the surfaces of your tub!
This soft sponge material can be safely used on inflatable pools and doesn’t contain any harsh or abrasive ingredients, just wet the eraser with some clean water and scrub it directly onto the stained area.
With a bit of elbow grease, the yellow stains will begin to lift, and you can simply wipe away any dirty residue with a soft cloth. We’ve seen some impressive results even on tough stains using this thing, and it works on plenty of other surfaces around your home too!
3- Baking soda and white vinegar solution
Baking soda is great as it’s a completely natural solution. Mix baking soda with white vinegar in equal parts, and rub the paste directly onto the stained hot tub surface. The mixture will break up the yellow stains, which can then be wiped away with a damp cloth.
Baking soda is also a natural deodoriser, so it works great as a stain remover and eliminates any stinky smells or stains left behind by bacteria and gunk, leaving you with a fresh and stain-free tub! A big thumbs up for baking soda.
How To Prevent Yellowing In The Future
The best way to prevent yellow stains is to do regular maintenance for your jacuzzi and check your hot tub or pool’s pH balance on a regular basis, use test strips to check for a pH level between 7.2-7.8, and have your or bromine sanitiser on hand to help balance the hot tub water if this reading is off.
A well-sanitised pool won’t support the bacteria and germs that can turn your hot tub a different colour, so making this part of your cleaning routine will go a long way to keeping your tub stain-free!
If the minerals in heavy water leave you with a yellow stains in a hot tub, try using a hose attachment with a built-in filter when refilling the water, as this will get rid of the offending minerals before they have a chance to mess with your jacuzzi.
Lastly, keep your tub covered when you’re not using it to avoid stains or even one stain for that matter. Whether that’s summer, winter or spring, the weather can change drastically very quickly.
This will protect the PVC from changing colour in the sunlight and help to keep the water free from any dirt and debris that could cause stains or future bacterial growth on the hot tub! Remember, the cover will need to be also cleaned; this page talks about hot tub cover cleaning and protection.
More Tips to Keep Your Hot Tub Clean
This page is about yellowing inside a hot tub. For a more general guide about how to clean your inflatable hot tub, it’s here.
Last Word
With the cleaning tips and tricks in this guide, you should be all set to remove any hot tub spa stain causing you grief. Check for the most likely cause, be it bacterial growth, rust, mineral-heavy water or excessive UV exposure, and get cracking with the above solutions!
We hope we’ve helped you understand the causes of yellow stains in hot tubs, so you can prevent the issue in the future and get back to having fun in your sparkling clean hot tub.