How to Remove and Prevent Hot Tub Stains


Owning a hot tub is supposed to be all about relaxation and luxury. Yet, there you are, staring at unsightly stains in your hot tub’s shell, wondering, “How did those get there?”

It’s frustrating, to say the least. But here’s the thing – hot tub stains can occur even when you’re diligent about cleaning and maintenance.

Sometimes, it’s just about making a few tweaks to your routine. So, before you throw in the towel, let’s break down how to tackle and prevent those stubborn stains.

Understanding Hot Tub Stains

Believe it or not, your hot tub can become stained even if you’re doing everything by the book. Regular cleaning is crucial, yet certain factors can still lead to staining.

hot tub stain

First off, let’s talk about why your hot tub might be getting stained. There are a few culprits to look out for:

  • Minerals: These little rascals come from your water source. Iron, copper, and manganese can leave behind stains that range in color from green to brown to black.
  • Rust: High levels of metals like iron and copper in your water, often from well sources, can react with chlorine. This reaction leads to oxidation, or rusting, resulting in greenish, brownish, or bluish stains.
  • Organic Material: Leaves, algae, and even lotions or oils from our skin can lead to stains. Typically, these will be green or brown.
  • Chemical Imbalance: Not keeping your water balanced can lead to a whole host of problems, including staining. pH levels, alkalinity, and sanitizer levels need to be kept in check.

How to Remove Hot Tub Stains

Before you start scrubbing away, it’s essential to understand what type of stain you’re dealing with. Use testing strips or a kit that measures for metals like iron and copper, especially if you suspect your well water might be contributing to the problem.

For Mineral Stains

  • Identifying the Stain: If the stain is reddish-brown, it’s likely iron. Blue-green? You’re dealing with copper. A good metal sequestrant can help you here.
  • Treatment: Lower your hot tub’s pH to about 6.8, then add a metal sequestrant according to the product’s instructions. This binds the metals, making them easier to filter out.

For Organic Stains

  • Shock Your System: A non-chlorine shock treatment can work wonders. It breaks down the organic material without affecting your sanitizer level.
  • Brush It Off: Sometimes, a good old manual scrub is needed. Use a soft-bristled brush to avoid damaging your hot tub’s surface.

Gathering Your Cleaning Supplies

Your stain removal kit might include:

  • Spa shock
  • Line flush product
  • Nylon scrubbing sponges
  • Filter cleaner
  • Specific cleaners for scale, rust, and scum

The Removal Process

  1. Shock the hot tub to kill any lurking bacteria.
  2. Clean the plumbing with a line flush product.
  3. Power Down your hot tub and its electrical supply to ensure safety.
  4. Drain the hot tub, then apply the appropriate cleaners for your stain types, scrubbing thoroughly with the sponges.
  5. Rinse well to avoid cleaner residue, which can lead to foaming issues.
  6. Dry the fixtures and non-water-filled areas thoroughly.
  7. Refill the hot tub, using a hose filter if dealing with hard water or high metal content.
  8. Balance the water chemistry and test again, adjusting as needed.

Preventing Future Stains

Prevention is key to keeping your hot tub inviting and stain-free. Here are some strategies:

For Hard Water

Consider adding a calcium hardness reducer or scale prevention chemical to your water, following the manufacturer’s instructions for the correct amount.

Use a Pre-Filter: Filling your hot tub? Use a pre-filter on your hose to screen out those pesky minerals before they get a chance to make themselves at home.

For High Metal Content

A metal sequestrant can help by causing metal molecules to clump together, making them easier to filter out. This doesn’t remove metals from the water but helps prevent them from staining surfaces.

For Scum

Scum can be tricky to avoid entirely due to body oils and products. Floating sponges or a few tennis balls can absorb these residues before they have a chance to stain the shell.

Water Chemistry

Perhaps the most critical aspect of prevention is maintaining balanced water chemistry, particularly the pH levels. Regular testing and adjustments will keep stains at bay.

Words of Wisdom

  • “An ounce of prevention is worth a pound of cure.” Regular maintenance and water testing are far easier than stain removal.
  • If you’re dealing with stubborn stains, patience is key. Some stains may require multiple treatments to remove fully.
  • Be mindful of the materials your hot tub is made from and choose cleaning products accordingly. What works for an acrylic tub may not be suitable for fiberglass.

By understanding the causes of hot tub stains and how to effectively remove and prevent them, you can keep your hot tub looking pristine and inviting.

Regular maintenance, proper water chemistry, and a bit of elbow grease when needed are all part of the equation. So, here’s to clear, clean waters and uninterrupted relaxation in your hot tub.

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