Adding hot tub chemicals for the first time – what you need

Picture this: you’ve just purchased your new Modtub and can’t wait to sit back and relax in it. If you’re a hot tub beginner, it may be tempting to fill the hot tub with water and start using it, but there’s more to it than just filling it. Getting your hot tub started requires testing the water and using chemicals to make sure your water is clean and safe. Luckily, when you buy from Modtub, your start-up chemicals are included with the purchase of your hot tub. 

Opening your hot tub involves the process of filling the hot tub with water, testing that water, and sanitizing the hot tub by putting chemicals in the water. This process may sound overwhelming if you’re a hot tub beginner, but the good thing is that the chemicals used to open your hot tub are the same ones used for your hot tub maintenance. It’s important to know which chemicals to apply and when to apply them to avoid a hot tub disaster. We’re here to tell you the chemicals needed to open your hot tub, what they are, and the steps you need to take to properly open your hot tub. 

What You Should Know Before Adding Chemicals to Your Hot Tub

Before we get to the chemicals you’ll need to add to your hot tub, there are a few things you should know. First, you should know why you need to add these chemicals to open your hot tub. Using a hot tub without chemicals to keep it clean is unsafe. Your hot tub is the perfect host for bacteria, algae, and other harmful microorganisms. If you don’t properly open or maintain your hot tub, not only can this be harmful to you, it can damage the hot tub equipment. 

A few other things are helpful to know before adding chemicals to your hot tub, like the water compacity. Knowing how much water your hot tub can hold is essential because this will determine the amount of each chemical you will put in your hot tub. There are three Modtub sizes to choose from M1, M2, and M3. Here is the water capacity for each:

• M1: 300 gallons
• M2: 450 gallons
• M3: 500 gallons

One thing we can’t stress enough is being safe while adding chemicals to your hot tub. Always be sure to wear gloves, goggles, and a mask when handling chemicals to avoid injuries. You should also follow the package instructions for the chemicals to ensure that you handle them properly. Never mix chemicals outside of water because this can potentially be dangerous or can cause the chemicals to be less effective. Lastly, make sure you are using chemicals for hot tubs and do not use pool cleaners or chemicals.

Chemicals Used For Opening a Hot Tub 

There are multiple chemicals needed to ensure you open your hot tub properly for the first time. Now that you know why these chemicals are so important for opening your hot tub and maintaining it, let’s talk about what the chemicals are and how they are used. There are many optional chemicals to add to your hot tub, but we’ll cover the required chemicals you’ll need to add to open your hot tub. Remember to take the proper precaution when handling any chemicals. 

Hot tub sanitizer

Sanitizing your hot tub is necessary to kill the bacteria and purify the water in your hot tub. There are a few different sanitizer options, like mineral systems and saltwater systems. The most common sanitizers are chlorine and bromine, so we’ll focus on those two. 

• Chlorine – This is the most common type of hot tub sanitizer because it is easy to use and very effective at killing bacteria and algae. It’s also cost-effective. The downside to using chlorine is the smell. Chlorine kills these contaminants by oxidizing, which gives off waste products called chloramines that cause the odor. If you can smell the chlorine, it probably means it’s time to add more chlorine because it has been used up. Because of this, it is best to use chlorine in outdoor hot tubs. The proper level of chlorine is 1-3 ppm. 
• Bromine – This is another common type of sanitizer used for hot tub owners. Bromine has a lower pH than chlorine, making it easier to keep your water balanced. The downside to bromine is that it doesn’t work as fast as chlorine and burns off pretty quickly under the sun. The proper bromine level is 3-5 ppm. 

Alkalinity increaser, pH decreaser, pH increaser

The pH and total alkalinity of your hot tub water are where it can get a bit tricky. You will need alkalinity increaser, pH decreaser, and pH increaser to balance your water. The pH of the water is how acidic it is, and the alkalinity acts as a buffer for the pH neutralizing incoming acid and preventing your pH from changing dramatically. This means that these two go hand in hand, and if one changes, it will affect the other. Total alkalinity levels should be between 100-150 ppm and pH levels between 7.4-7.6. If your pH is too low, it can cause erosion in your hot tub equipment. Levels that are too high can cause itchy, drying skin and irritation to the eyes. 

You’ll need to use test strips to balance your pH and alkalinity. After testing your water, add a pH increaser or decreaser to achieve levels between 7.4-7.6. If your alkalinity is too low, add in your alkalinity increaser until you’ve reached the desired levels. Since there is no such thing as alkalinity decreaser, if your alkalinity levels are too high, you’ll have to add in pH decreaser. Be mindful that this will decrease your pH. It may take time to get everything balanced. 

Calcium hardness increaser 

Most of the time, hard water can be a burden because of the calcium deposits it leaves on shower heads and faucets. In this case, you want some of the hard water in your hot tub. If water is too soft, it can eat away at your hot tub parts. Calcium hardness levels should be between 175-250 ppm. You can find calcium hardness levels using a test strip like the other levels. If levels are too low, add in the calcium hardness increaser. Make sure to add this in slow because if levels become too high, the solution is to drain your tub and start again. 

Levels of chemicals 

The Correct Order For Hot Tub Chemicals 

Not only do you need to know what these chemicals are, but you must also know what order to add them to your hot tub when opening it for the first time. Adding chemicals to your hot tub in the wrong order can result in a disaster. 

First, you’ll need to fill your hot tub with water. Use a hose filter if you have it to remove impurities like metals in your water. Suppose you don’t have a hose filter. In that case, you can use a metal sequestrant or stain preventer to your water before adding other chemicals. Metals that aren’t neutralized in your hot tub can stain your hot tub or damage equipment. 

Before adding other chemicals, you must test your water using a test strip. Use the test strip results and your hot tub’s water compacity to determine how much of each chemical you will need. Make sure to retest your water after you’ve added chemicals to ensure everything is balanced and in the proper ranges. You will add the chemicals in this order:

1. Metal sequestrant of stain preventer (if needed)
2. Alkalinity and pH
3. Sanitizer 
4. Calcium hardness 

Purchase Your Hot Tub Today

If you believe you’re ready for opening your own hot tub, call Modtub today. We’ve created the most transparent purchasing process in the industry. We’re locally owned in Dallas, Texas and support American manufacturers by keeping 100% of our products made right here in the USA. Check out how it works, where we’ll tell you how to get your Modtub in 3 easy steps.