Hot Tub Chemical FAQs

Whether you’re a new hot tub owner or an experienced user, understanding water chemistry can sometimes be confusing. In this article, we will answer some of the most common hot tub chemical questions so you can keep your hot tub in top shape.

What Do Hot Tub Chemicals Actually Do?

Our first common hot tub chemical question is also the most basic; what is the purpose of adding chemicals to your hot tub water? Hot tub chemicals are each designed to serve one of three purposes:

• Sanitization. These chemicals (either bromine or chlorine) are designed to kill bacteria; keeping your hot tub water clear and safe to bathe in.
• Problem solving. These chemicals are designed to treat specific water quality issues; such as foamy or cloudy water.
• Balancing. These chemicals are designed to “balance” your hot tub water; making it more comfortable to bathe in while also extending the lifespan of the key components of the hot tub (pumps, heaters, etc).

Should You Use Bromine Or Chlorine?

The two most common types of sanitizers used in hot tubs are chlorine and bromine; with the most popular by far being bromine. Why is bromine so much more popular than chlorine?

• Bromine is generally less harsh on your skin than chlorine.
• Bromine is slower to break down in hot tub than chlorine is; meaning that you can keep lower, more consistent levels of sanitizer when using bromine.
• Bromine is more effective at higher pH levels which are common in hot tubs.

So why does anyone use chlorine? Firstly, the difference between the two is not all that great. When making these comparisons we’re talking about relatively small differences that, while noticeable, don’t add up to a night and day difference. The most common reason for people to use chlorine, however, is that some people have a sensitivity to bromine that can cause skin irritation; making chlorine the only reasonable option for them.

What Does “Shocking” Hot Tub Water Do?

“Shocking” is a term for adding a large amount of sanitizer to the hot tub water. This process releases trapped gases like nitrogen that can reduce the effectiveness of your sanitizing chemicals while also burning off any small amounts organic materials that the regular sanitizers may have missed. Without regular shocks; your sanitizers become less and less effective over time, leading to cloudy and potentially unsafe water.

How Often Should You Add Hot Tub Chemicals To The Water?

Given average use (3-4 times per week), we recommend adding your regular maintenance chemicals (commonly sanitizing pucks made of either bromine or chorine and a “shock” of some kind) once per week. That said, if you use your hot tub frequently you may need to add these chemicals more often than that. Balancing chemicals, on the other hand, are only when they’re needed; commonly one or twice per month.

So how can you tell when you should add your hot tub chemicals? With regular water tests! Home test kits should be done 2-3 times per week. The goal of these tests should primarily be to ensure that your hot tub water has enough sanitizer (bromine / chlorine) in it. If the sanitizer level is low, simply add a small amount of powdered sanitizer to bring the levels back up. If your levels are consistently low, you may want to consider increasing the amount of sanitizer that you add in your weekly maintenance checks. If this still doesn’t solve the issue you can try adding your maintenance chemicals every 5 days rather than once per week.

Your home test kits can also let you know if the balance of the water is off. If you notice that the balance is slightly off you can try adjusting it yourself with small amounts of balancing chemicals; however we generally recommend taking a sample into your local hot tub retailer to get a professional test. These tests are much more accurate than home test kits, and test for more things. Following the recommendations of these tests will ensure that your water stays balanced, without the need for guesswork.

How Long Should You Wait Before Using The Hot Tub After Adding Chemicals?

We generally recommend waiting around 30 minutes to use your hot tub after adding any chemical to the water. This gives the chemical enough time to evenly incorporate into the water before you get in to relax. The major exception to this rule would be after you shock the water. Since shocking involves adding a considerable amount of sanitizer all at once, we recommend giving it around 12 hours before you use the hot tub again. This gives the sanitizer levels time to reduce down to a level that is comfortable to bathe in.

Can You Add All Your Hot Tub Chemicals At Once?

To avoid any unwanted chemical reactions, we recommend allowing each chemical at least 15 minutes to incorporate into the water before adding the next chemical.

What Chemical Can You Use To Get Rid Of Foamy Water?

Foamy water happens when oils and lotions build up in your hot tub water. When air is added to the water, these oils and lotions cause bubbles to form on the surface of the water. When enough oils and lotions are present in the water, enough of these bubbles will build up to cause a thick foam to form on top of the water’s surface.

So what can you do to stop this? In the short term, you can add anti-foaming chemicals to break the surface tension of the water, preventing bubbles from forming. While this does stop the foam from building up, it doesn’t cure the cause of the foam. For that you will need to remove the oils and lotions from your hot tub water. This can be done in a few different ways:

• Oil absorbing sponges. These special sponges float in the hot tub when you’re not using it, absorbing any oils they come into contact with.
• New / cleaned filters. Your hot tub filters are able to catch some amount of oils and lotions, though they will need to be regularly cleaned in order to get ahead of a foam issue. If the filters are more than 12 months old, they will likely need to be replaced to be able to help deal with a foaming issue.
• Drain and refill the water. If the water in you hot tub is 3-4 months old it’s probably best just to drain and refill it with fresh water.

What Chemical Can You Use To Get Rid Of Cloudy Water?

Cloudy hot tub water is caused by one of two things:

• A build up of organic materials in the water; commonly dead bacteria.
• A build up of minerals like calcium caused by high alkalinity and/or high calcium hardness.

Water clarity chemicals can be added to the water to improve clarity in the short term, though as with the anti-foaming chemicals; these only mask the problem rather than solving it.

To treat cloudy water you will first need to determine the cause. We recommend getting your water professionally tested anytime the water turns cloudy. If the tests reveal high calcium hardness / alkalinity you can add balancing chemicals to bring them back into balance. If the tests show low sanitizer levels, you may simply need to shock the water to remove those built up organic materials.

Wrapping Up

Hot tub chemicals are essential to the operation of your hot tub. Hopefully today we were able to take some of the mystery away from them. If you still have any questions about hot tub chemicals, or hot tub ownership in general, feel free to reach out and talk to one of our dedicated hot tub experts!