In today’s post, we follow up on our popular Beginner’s Guide to Spa & Hot Tub Care, and get more granular with Spa Chemicals for Dummies.
The book pictured is not a real book, not one that you can purchase anyway. Don’t think I’m calling our blog readers Dumb; just a fun blog title.
Because such a book does not exist, this post will explore some basic hot water chemistry topics that may confuse a novice spa or hot tub owner.
Like how to test spa water, or what chemicals are needed for a hot tub. How to treat common spa water problems, and info about alternate sanitizers like ozone or minerals.
So, without further ado – here’s our beginner’s guide to Hot Tub Chemicals, or Hot Tub Chemistry for Dummies!
Spa & Hot Tub Chemicals
We have over 100 different spa chemicals in our online store, no wonder it’s confusing! Below is a primer on 6 categories of spa chemicals, with a short description of when they are used, and for what purpose.
Balancers: Spa chemistry is not overly complicated, but when I speak about ‘water balance’, some people’s eyes glaze over. Balanced spa water is simply when your spa chemical readings are all within the proper ranges. Specifically, spa chemical ranges are pH at 7.4-7.6, Alkalinity at 80-120 ppm, and Calcium Hardness at 150-250 ppm. When all 3 are in range, your water is ‘balanced’. If you really want to geek out however, you can use a Saturation Index calculator to determine water balance more accurately. Of spa balancer chemicals, pH down is probably the most used of the balancers, as spa pH and Alkalinity tends to rise, and pH down reduces both. If spa water is soft, raise it with Calcium Increaser, for low hardness levels. For a low pH and/or Alkalinity test, use pH up and/or Alkalinity Increaser to raise the levels.
Clarifiers: If your spa water is cloudy, or lacks clarity and sparkle, it may be time for a new spa filter cartridge, or there may be issues with water sanitation. Clarifiers are polymers that have a positive charge and attach themselves to negatively charged water particles floating around the hot tub. What starts as a microscopic particle eventually ends up as a large clump of hundreds of particles, large enough to get trapped in the filter. So then, clarifiers are used for spa filters that need a little help, or if water conditions turn poor. Be careful not to overdose with clarifier however, or it may have the opposite effect, and it can gum up your spa filter. If your hot tub water is always sparkling, you may have no need to use a clarifier chemical.
Cleaners: In this category of spa chemicals, we have hot tub cleaners for your spa filter cartridges, spa cover cleaner and conditioner, spa shell cleaners and polishers, Leak Seal to seal up small leaks and Jet Clean to purge or strip plumbing lines. Be careful never to use household chemicals to clean your spa or accessory items, with the exception to a mild soap (with lots of rinsing afterwards to prevent spa foaming). In my own spa, I do use spa filter cleaner, spa cover conditioner (my tub gets a lot of direct sun), and I use Jet Clean once per year to prevent a biofilm buildup in the pipes.
Sanitizers: A sanitizer is the everyday chemical used to kill pathogens like bacteria, fungus, mold, viruses, etc. Most spa owners will use either bromine or chlorine as the main sanitizer. Granular chlorine is hand fed (don’t use chlorine tablets in a spa) when chlorine is preferred, or you can use bromine tablets (the easiest route), or add bromide salts and then a small amount of regular shock (chlorine or MPS) to activate the bromide salts into bromine. You must keep an active level of sanitizer at all times in spas and hot tubs. If the level drops to near zero, pathogens, algae and other contaminants immediately begin to grow and multiply, even in hot water, and even when covered tightly.
Shocks: Spa shocks are also sanitizers, but they are used differently in spas and hot tubs. Chlorine or non-chlorine (MPS) spa shocks are quick dissolving and quick acting, and are used to kill anything that your daily sanitizer has missed, or to supplement your daily sanitizer, after a 4-person soak for example. Spa shocks are also used to activate bromide salts, and convert them to bromine. If you use bromine tablets however, this is not necessary, but shock is still useful to give the spa a sanitizer boost after heavy use, or as a weekly or bi-monthly shock treatment, just to be sure the water is sanitary. A third use of spa shocks is to kill algae, or remove foul odors, water discoloration or poor clarity, or variety of water issues with from many causes. For best results, always check water balance and adjust if necessary before shocking a spa. Follow label instructions for treatment info and dosage to match your spa size, in gallons/liters.
Specialty: Specialty spa chemicals are those chemicals that don’t fit neatly into other categories. Chemicals like Foam Out or Foam Down (removes surface foam) or Metal Gon / Defender (keeps metals in solution), or enzymes like Natural Clear that dissolve oils naturally, or Algaecides to prevent algae growth in hot water spas. You may have some need for these chemicals at some point, to remove foam, stains, oils or algae, or you may be lucky and may only rarely need specialty chemicals – you know where to find them!
How To Test Spa Chemistry
There are two ways to test hot tub water, with Test Strips or a Test Kit. Unless you fancy yourself a chemist, I usually recommend the AquaChek 6-in-1 Test Strips, which test for all the important stuff in just 1-2 minutes. The secret to spa chemistry is not sold in a bottle; test your spa water 2-3 times per week. You will begin to see patterns in your chemical fluctuations, especially if you keep a test log book. But even if you don’t write down your readings, or enter them into an app, over time you’ll come to know your own hot tub chemical personality.
How To Store Hot Tub Chemicals
- Keep out of Reach of Children.
- Cool & Dry Location 50-80° F
- Open Only One Container at a time
- Tight Lids Keep Out Moisture, Children and Prevent Spills
- Protect Chemicals from Spills and Mixing and Contamination
We’ve covered the topic before with some neat spa chemical storage ideas, but the general idea is to, number one, keep out of reach of children. Secondly, store spa chemicals in a Cool and Dry location, that usually means indoors. 50-75° is best for chemical shelf life and to prevent gas formation or hardening of granules. Always open, use, and close tightly only one chemical at a time; tight lids keep out moisture and children, and prevent spills. Don’t hold onto old spa chemicals, use or dispose of them, and keep chemicals close to the ground, not high on a shelf where they may fall and spill their contents, especially if you live in an earthquake zone. Very Important – never allow spa chemicals to mix with each other, or become contaminated with any substance (dirt, leaf, soda, ashes) that accidentally mixes with spa chemicals. A fire or explosion could result.
What Chemicals Do I Need for a Spa or Hot Tub?
- Spa Sanitizer – Bromine or Chlorine
- Spa pH increaser and decreaser
- Spa Alkalinity and Calcium Increaser
- Spa Shock – Chlorine or MPS
As a minimum, you’ll need most of these spa chemicals. You may use primarily pH down and not so much pH up, probably adjusting 2-3x per month. For Alkalinity and Calcium levels, those usually hold steady for a month or more, once adjusted after a spa water drain and refill. And you will use Spa Shock for weekly use and a different Spa Sanitizer for daily use. You may also have a need for other chemicals from time to time such as Filter Cleaners, Metal Removers, or Clarifiers. Many of our customers like the convenience of our Spa Care Kits, complete 6-month chemical packs for Bromine or Chlorine or Nature2 spas that include a water fill Pre-Filter and up to a dozen other items.
What are Natural Spa Chemicals?
- Mineral Sticks
For those that want to avoid the smell of chlorine or the slightly softer smell of bromine on your skin, you can approach water sanitation from a different angle. Instead of using chlorine or bromine, you can use Spa Mineral Sticks, which use Silver/Copper ions to help purify the water, or you can use ozone, injected into the pipe from an Ozonator. Both of these systems, coupled with regular shocking with MPS, a non-chlorine oxidizer, and some extra filtering and attention to good water balance, can allow you to operate most spas without the use of chlorine or bromine. Also in the natural chemical category are Enzymes, which are natural scum-eaters, helping to remove contaminants in the water by naturally digesting them.
If you made it all the way to the end of this post, you are now 10x smarter than the average Spa Chemistry Dummy! One good thing about spa chemistry is that if things go really bad, you can always replace the water, and should anyway, every 90 days or so. Remember to re-balance your chemistry, or rebuild your ‘bromine bank‘ after refilling.
Talk to you later;