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Archive for the ‘spa chemicals’ Category

Spa & Hot Tub Chemicals for Dummies

August 29th, 2016 by

spa-chemicals-for-dummies-book2In 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

snake-oil-salesman-smThere 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

  1. Keep out of Reach of Children.
  2. Cool & Dry Location 50-80° F
  3. Open Only One Container at a time
  4. Tight Lids Keep Out Moisture, Children and Prevent Spills
  5. 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?

  1. Spa Sanitizer – Bromine or Chlorine
  2. Spa pH increaser and decreaser
  3. Spa Alkalinity and Calcium Increaser
  4. 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?

  1. Mineral Sticks
  2. Ozone
  3. Enzymes

ozone-minerals-mpsFor 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.



dummies-guyIf 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;


– Jack

Saltwater Chlorine or Saltwater Bromine?

July 25th, 2016 by

saltwater-chlorine-or-saltwater-bromineSalt water chlorine vs. salt water bromine. Which is better?

The chlorine vs. bromine debate, along with the pros & cons of using a hot tub salt system have been hashed out before on this blog, but what if you already love spa salt water generators, and wonder about using sodium bromide, instead of sodium chloride as the necessary salt.

Bromine is better than chlorine in a hot tub, as it stays potent in high temperatures and in a wide range of pH values, and has less odor. So why not use Sodium Bromide instead of Sodium Chloride in a spa or hot tub with a salt generator?

  • Sodium Bromide salt is much more expensive than Sodium Chloride salt. This is because of the higher cost of raw materials. It costs only $5 in NaOCl after draining the spa (unless you use Dead Sea Salts, which are much more costly), but to replace the NaOBr, it can cost $25, each time you drain.
  • Bromine Generators cost twice as much to purchase than equivalent spa chlorine generators. Roughly $200 for salt systems, and $400 for bromine systems.

But wait ~ aren’t Bromine tablets also twice as expensive as using spa chlorine tablets? Yes. Bottom line is that Bromine costs more than chlorine, no matter how you introduce it to the water.

For many spa owners, it’s worth the extra cost to have a Bromine spa.

Spa Chlorine and Bromine Generators

saltron-mini-power-supply-and-cellCan you use bromide salts with a salt chlorinator? You could, after draining and refilling with fresh water, add sodium bromide ions to the water to create bromine, instead of chlorine. However, salt chlorine generators such as the Saltron Mini are optimized to work with sodium chloride, although the manufacturer told me that either salt can be used.

Is there a difference between Salt Brominators and Salt Chlorinators? There are small differences in the salt cell coatings and in the salt level required for operation, but the operation or technology is the same. They both convert ions into a sanitizer, which afterwards revert back to the base salt, where the process can begin again. Spa Salt Bromine Generators, such as Blu Fusion (formerly the unfortunately named ISIS salt system), and the Gecko Alliance in.clear bromine salt system for spas.

What type of Salt is used in a Saltwater Hot Tub? If you are using sodium chloride, be sure to use a pool salt with a high 99% level of purity, without added caking agents, desiccants or iodine added. For a bromine spa, add pure sodium bromide salts to the spa, the same bromide booster that is used to build the ‘bromine bank’ when using bromine tablets. Many spa salt system owners also use Dead Sea Salts, which contain potassium and magnesium, in addition to sodium.



Happy Hot Tubbin’

Daniel Lara





Can a 4th Grader Maintain a Hot Tub?

July 18th, 2016 by

Photo Credit to Carroll Photo via istockphoto
Most hot tubs are not too difficult to maintain, but can a 4th grader do it?

When my grandson Josh to came to stay with us for the most of the summer, I decided to give him some chores around the ranch.

I concocted a little experiment, to see if a 9 year old could manage a spa as well as his grandma could. When I asked him if he’d like to learn how to take care of the hot tub (which he loves), he enthusiastically agreed.


The first part of the hot tub education is what to touch, and what not to touch.

  1. Electrical: I showed him where the power cut-off is on the wall, and we traced the cable into the spa pack underneath. Then is showed him the exposed terminals on the spa heater and told him they could be shocking if he touched them. Also told him to stay out of the controller box, after lifting the lid to show him the inner workings (just to satisfy any curiosity).
  2. Plumbing: I showed him the two cut-off valves under the spa, and how to close and re-open the valve, and then asked him not to touch them again, after explaining the problems (burned out pump, broken pipes) that could happen if the valves were left in a closed position with the spa pump running.
  3. Chemical: I told Josh some horror stories of explosions and fires that I’ve heard about over the years, from chemicals mixing with each other, or being contaminated with dirt, liquids or nearly anything! My spa uses very few chemicals; I only have bromine tablets, MPS shock, and pH and alkalinity chemicals, all kept in separate bins. He sensed the importance of spa and hot tub chemical safety and pledged to follow the spa chemical rules sign I posted:
  • Open one chemical at a time, tightly closing one before opening another.
  • Always read and follow label instructions.
  • Store chemicals carefully in the correct bin.
  • Keep Chemicals dry and clean, and never mix.
  • Ask Grandma if you have questions!


Josh is exceedingly bright, of course, all my grand children are! I showed him how to test the water with a spa test strip, and then compare the colors carefully, to the chart on the bottle. Then I told him to write down the chemical readings in a Spa Log Book which I made up from a spiral notebook.

He tested the chemicals every other day, and when a chemical went out of range, he would let me know. The first month we did all the chemical adjustments together, so he could see me carefully reading the label, adding one chemical at a time, and replacing it safely.htw-spa-ph-minus

My spa only needs bromine tablets every 2 weeks, and a weekly shocking, which we do after our last weekend soak. The pH, alkalinity and calcium hardness levels are usually OK between water changes, but once or twice we had to lower the pH level by carefully adding pH decreaser.

Now into our second month, Josh is still testing the water every other day and jotting down his readings in the book. He refills the brominator, and adds pH down when needed, which he also notes in the log book.


spa-filter-cartridge-smOur spa filter usually goes 4-6 weeks between cleanings. It’s a top load style, so when we cleaned it the first time, I showed him how to remove the cover, and he stood on a step ladder and pulled out the filter cartridge.

Then I told him to take off his shoes, and have a seat in the sunshine. “Spray this cartridge from top to bottom, pleat by pleat, all the way around. Then flip it over and do it again. It takes about 15 minutes…”. Well, proud to say that he spent 23 minutes on it, and it looked really clean.

We’ll clean the filter again in a few weeks, I think he’s got it!


Like most Jacuzzi tubs, they stay pretty clean, especially since it’s covered most of the time. But we still do get some sandy grit, and a light scum line around the water line.grit-getter

Even though it doesn’t really need it weekly, Josh gets in the tub (supervised by me or my husband), and uses the Grit Gitter to get rid of the grit and then a Tub Scrubber to clean the waterline.

Cleaning the spa takes Josh about 15 minutes, which is our maximum spa time anyway, so it’s perfect that way.


i-can-take-care-of-hot-tubsJosh, 9 yrs. old; has definitely proven that a spa can indeed be maintained by a fourth grader (so proud of him!). But before you draft your kids or grand kids into the spa service, think about the hazards or potential problems that could happen around your particular spa, and adjust any tasks to their age and aptitude.

Talk to you later;


Carolyn Mosby
Hot Tub Works






Off Season Hot Tub Maintenance Tips

June 20th, 2016 by

For seasonal users of hot tubs, some adjustment to your maintenance routines can be made, during times of non-use or very low use.

But that doesn’t mean you can ignore the spa sanitation and filtration altogether! Leave a spa to it’s own devices, without intervention, for too long and you’ll have bacteria buildup, damaged filters or at least a very smelly hot tub.

If you tend to use the spa less during warmer weather (or less during colder weather), here’s some tips on protecting your investment and avoiding costly clean-up of a spa gone too long without care.



draining-a-hot-tubIt’s tempting to leave the water in the hot tub or spa after the season, and drain it before using it again, but depending on how old the water is, and how long the tub will sit (all summer?), you may want to drain it now, as a step to ‘summerizing’ the spa. If your spa water is over 90 days old, and has been used semi-regularly, I would advise draining and refilling with water from a Pre-Filter. After refilling, balance the pH, alkalinity and calcium hardness, and shock the spa water with MPS.



A covered spa that is not heated will drop and stabilize to a temperature that is a bit lower than the outside air temperature. During freezing weather, it’s important to keep the spa pump running, to avoid freeze damage. During hot summer weather, even with the heater off and spa covered, water temps can rise into the 80’s. It’s important to keep the spa pump running, to avoid algae and bacteria from growing during hot summer months.



spa-water-testsEven though no one is using the spa, protect your shiny surfaces, cover, filter and rubber bits by checking the pH, alkalinity and calcium hardness levels on a monthly basis. After you balance the water, add a full dose of spa shock, to disinfect and oxidize the spa water, destroying any germs in the hot tub. Keep the hot tub cover open for about an hour after shocking, to allow the water to gas-off. If the water was cloudy during the monthly inspection, increase filter run time and/or sanitizer levels and consider using a clarifier to help the filter.



Because you aren’t using the spa, you may not need to run a 3-5 ppm level of bromine, because the contaminants introduced to the water are very low. However, you will still need to keep some type of constant sanitizer in the water, to kill bacteria, viruses, algae. A spa Mineral Stick is a good idea to manage daily disinfection, with a monthly balancing and shocking of the spa. An ozonator can also accomplish the majority of the daily sanitation needs for the un-used hot tub, coupled with regular spa shocking. Bromine tubs can also just use fewer tablets in the floater or feeder, just 1 or 2 bromine tabs, to keep a low-range 1-2 ppm of bromine in the water. If you fill a spa floater with 9 tabs and close it the vents all the way, you should be able to deliver about 1ppm of bromine to the spa, constantly. Avoid allowing the spa water to filter only, without bromine, ozone, minerals or shock, it won’t last long without some form of daily sanitation.



spa-is-closed-signA tight fitting spa cover is important not only for spa safety, but also to keep out debris and sunlight. Be sure to clamp all of the cover clips around the spa cover. For protection from summer storms and high winds, use spa cover wind straps, and cover the spa cover with the Spa Cover Cap, to protect the cover from summer sun and rain, and also to make the spa more inaccessible or off-limits. If you want to be more explicit, post a Spa Closed sign, especially for rental properties or commercial spas that aren’t of the single-family type.



Just as you need daily sanitation for the off-season spa, you also need daily circulation and filtration of the water. And just as you need less sanitation for an unused spa, you can get by with less filtration for a spa that is sanitized and un-used. Program your circulation pump to run on low speed for 3-6 hours daily, with a daily high speed run of about an hour. With summer weather comes greater possibility of power outages which can affect your pump timer programming or leave the spa in an OFF mode. Keep an eye and an ear towards the spa to be sure that the filter is running like it should.

BONUS TIP: Before putting the spa to bed, remove and clean the cartridge filter, or replace the spa filter if it’s close to 24 months old.


Carolyn Mosby
Hot Tub Works





Hot Tub Ozonator VS. UV Light VS. Minerals

May 16th, 2016 by

When it comes to sanitizing your spa or hot tub, you have a lot of choices. When I first started hot tubbing, we didn’t have all these fancy purifiers, and until the 80’s we had to use pool chemicals!

Chlorine and Bromine are an easy way to keep the water constantly protected. But – there’s a dark side! It smells bad, bleaches suits, dries skin and hair, and can be unsafe to store and use.

And that’s why a cottage industry sprung up, offering alternatives to traditional sanitation methods. Let’s talk about all 3 – Ozonators, Ultra Violet light, and Mineral Purifiers.

Hot Tub Ozone

del-mcd50-ozoneHow it Works: Ozone is called the ‘World’s Most Powerful Sanitizer’ and indeed packs quite a punch. An ozonator or ozone generator shoots a small electric charge across an air filled gap to separate oxygen O² into O¹. The singular oxygen atom quickly bonds to a nearby O² molecule, to become O³, or Ozone. The additional oxygen atom makes O³ very unstable, destroying any unfortunate particle that gets in the way.

Down Side: Ozone is cheap to produce, however the circulation pump must be running, to draw the gas into the line. When the pump is off, ozone is not being produced. Ozone also has a very short life, and due to the gaseous state, it will rise to the surface and gas-off quickly.

Maintenance: Spa ozonators require replacement of the ozone tubing and check valve every 1-2 years. CD (Corona Discharge) models require CD Chip replacement every 1-2 years, while AGP (Advanced Plasma Gap) units can last up to 5 years.

Effectiveness: Using a spa ozonator can allow you to reduce reliance on high levels of chlorine and bromine, by as much as 50%, according to manufacturers. Ozone destroys Giardia, Pseudomonas and Crypto and is a powerful oxidizer.

Hot Tub UV Light

spectralightuv-lampHow it Works: UV light purifiers work by irradiating the water, as it rushes by a UV lamp that is producing a specific wavelength 254 nm within the UV-C spectrum. When exposed to UV light of this specific wavelength, living particles actually have their DNA rearranged and become unable to reproduce. This renders the particles as inert, and only from a millisecond of exposure to the UV-C light.

Down Side: Like Ozone, UV light is cheap to produce, but is only being produced while the pump is running, pushing water over the UV-C light bulb or lamp. UV system strength can be reduced by high water flow rates, cloudy water and water temperature. And it has no ‘shelf life’, sanitation only takes place for an instant, while the water is passing under the eerie blue light.

Maintenance: Spa UV light systems use a special bulb to create the UV-C light. In most cases, these bulbs will need to be replaced every 1-2 years, as they begin to lose effectiveness over time. Cleaning the quartz lens regularly is also recommended, to remove dust or grime deposits.

Effectiveness: Like Ozone, UV purification is a tried and true secondary sanitizer, and can reduce your reliance on chlorine or bromine. It also inactivates (renders inert) parasites and pathogens like Ozone, when sized and used properly.

Hot Tub Mineral Purifiers

spa-mineral-sticks-for-hot-tubsHow They Work: Mineral purifiers for hot tubs and spas are slim cartridges that you drop into the hole in your cartridge filter. They’re filled with Silver and Copper pellets which slowly dissolve at a controlled rate. The silver and copper act together as a biocide, with silver oxide as the sanitizer and copper working as an algaecide. Using a mineral stick, like the others, can allow you to reduce chlorine or bromine usage by up to 50%.

Down Side: Mineral sticks for spas are also not as powerful as ozone, and cannot kill the strongest of pathogens that may come into the water, although they come close.

Maintenance: Most mineral sticks are replaced every 4 months, when the silver and copper depletes. No other equipment involved, so no other maintenance is needed.

Effectiveness: Unlike ozone and UV, mineral sticks create lasting protection by maintaining a residual of silver in the water. You will notice an immediate improvement in water quality and can appreciate using less sanitizer or filter aids to keep the water clear.


Your mileage may vary, but having a secondary sanitizer makes sense and is recommended by the MAHC (Model Aquatic Health Code). It can help reduce reliance on harsh chlorine or bromine, and also acts as a nice back-up for those occasional gaps in coverage, if you know what I mean.

In most cases, all of these systems tend to cost the spa owner about $100 per year, but you can realize some savings in other chemical costs, and will enjoy the peace of mind knowing that your spa water is extra-clean, I know I do! I use Nature2 and Del Ozone on my own spa.


– Jack



Natural Hot Tub Maintenance

March 3rd, 2016 by

my-natural-hot-tub-istkMy hot tub is not 100% natural, but it’s close. I use very few bottled spa products, either for cleaning the water, or for cleaning the hot tub.

Having a “Natural” hot tub or spa is more than just adding a mineral purifier or ozonator, or using enzymes – all of which I use.

If you really want to reduce reliance on spa chemicals, you have to take some action to replace the work done by spa sanitizers, clarifiers, algaecides, defoamers, etc..

Here is my short list of things that I do to maintain my Natural hot tub:


  • I know, not very “green”, to run the pump longer each day, but stagnant water starts to get funky quick without strong sanitizers in the water. For this reason, I run my circulation 3x as much as most people. I also run the pump on high speed almost every day to loosen any filmy or crusty deposits, opening the air intakes (or you can turn on a blower), to aerate the water. And when we use the spa, I add MPS afterwards and leave the spa running for about an hour, with the cover open.


  • This is really necessary to maintaining a natural hot tub. If you don’t want to run a high bromine level, or have to shock the spa after every use, take a serious shower before getting in the hot tub. And ladies, don’t forget to put your hair up (or wear a cap) and remove make-up before getting in the tub. If your natural tub is not au-naturel (you wear something), be sure not to use swim suits, shorts or shirts that have been washed with soap. If so, wash them again on a long cycle without soap.


  • A natural spa – one without bromine or peroxide sanitizers, has to replace the spa filter cartridges more often. Simply more stuff needs to filter out of the water, so your spa filter has to work harder. Spas that aren’t trying to be “Natural” may get up to two years out of a spa filter, but I always change mine every December.


  • clean-your-spa-with-a-lemon-istk istockCleaning your cartridge in a 50/50 vinegar solution is a natural way for those with very high calcium levels, or hard water, to keep their filters and jets from tiny crystalline deposits. Use baking soda (sodium bicarbonate) on a wet scrubber sponge as a way to clean and scour very dirty surfaces. Natural citrus based cleaners can also be used, in fact you can cut a lemon in half and use it as a tub scrubber!


  • Another very important part of natural hot tub care, is keeping the water balanced. If the pH or Alkalinity get too high, it makes a perfect environment for all sorts of things to grow. I keep mine between 7.2 – 7.4, and always check it before I get in the water. If there are 2 or more people using the spa, I check it again afterwards, it’s almost always higher. Add calcium hardness increaser if your level is below 150 ppm, and alkalinity increaser if below 80 ppm.


  • Your tap water may not be the best water for your spa, with chloramines, metals, minerals and other invisible gunk. Just like we filter our drinking water, we filter it before I put it into the hot tub! Just use the Pre-Filter on the end of your garden hose when filling the tub. I can’t over-emphasize how important this is to maintaining a natural hot tub! Start off with bad water, and it quickly becomes hard to maintain it naturally.


  • I have a Del Ozonator and I use the Nature2 mineral stick. Because I don’t also use bromine tablets or chlorine granules in my hot tub – I have to make sure these units are working properly, and replace them as needed. Every 4 months for the skimmer stick (my calendar alert pops up), and I just replaced my ozonator with the Next Gen model that lasts up to 5 years. I also add a small amount of spa enzymes to my spa weekly, natural proteins that consume microbes. And I use only as much shock as needed.


  • I use MPS shock, or non-chlorine shock, about every other time I use the spa, or about once per week. If that seems fairly often, it’s because I’m not using any bromine or chlorine in my hot tub. If I don’t use the MPS shock at least 1-2x per month, my water begins to look gray and dull, and I begin to ‘question its sanitary’, so I add just two tablespoons of MPS every week or so.


Also not green, or environmentally friendly, and possible illegal in your area – but there comes a point when the water is literally choked with solids and needs to be changed. The water gets so crowded, that  some of it gets thrown out of solution and becomes visible. First as a dull appearance, followed by a slight haze, progressing to cloudy water. When spa water becomes ‘old’, it becomes harder to keep clean and clear and harder to keep sanitary. For most natural hot tubs and spas, including my own, a drain and refill is done every 90-100 days.


ecofriendly-natural-hot-tub-istkNatural Spa maintenance doesn’t need to involve so-called ‘natural’ hot tub treatments, or systems that claim to do everything with one monthly treatment. It’s not easier than a bromine/chlorine spa – it is more work and more multi-layered than many would have you believe.

But it is quite possible, to maintain a spa or hot tub with very few spa chemicals – my tub is nearly all-natural, and my hubby and I love it that way!


Carolyn Mosby
Hot Tub Works




How to Read a Hot Tub Owner’s Manual

February 22nd, 2016 by


Unlike old spa owner’s manuals, the modern spa owner’s manual is a real piece of work. Some of the better ones are over 50 pages, with excellent color graphics, tables and step by step photo illustrations.

Early hot tub manuals from the 70’s and 80’s were laughably lackluster, and probably that’s why you can’t find them online. In the days before desktop publishing, you know.

A hot tub owner’s manual is a great resource for the spa or tub owner. But in talking to spa owners over the years, most of them don’t know where they put their Owner’s Manual, or had not thought to look at it for answers.



Always the first section, after the obligatory precautionary statements, are an abundance of tips about how to choose a proper location for the spa, and other considerations like overhead protection, drainage around the spa, access for service, and location of power and water. Some useful gems about spa installation that you can find in your owner’s manual include:

  • A 4-6 inch poured concrete slab of concrete with rebar or mesh on compacted and level soil
  • For easier draining of the spa, and for flood protection, locate your spa in an elevated area.
  • Electrical Requirements: 230V, 50-60 A, 4-wire, GFI protected and grounded dedicated circuit with external cut-off box.
  • Bonding Requirements: Bonding wire bare #8 copper wire to spa, and grid or nearby metal fixtures, per local code.
  • Set-Up: Some general tightening or parts installation before fill-up and start-up.


Operation of the Spa, knowing how it all works. This section has grown large now that spas are so full-featured, with lots of equipment and so many jets.  Fortunately, owner’s manuals are becoming very visual, with large clear photos, flow charts and even infographics!

  • Understanding the User Interface: aka the Topside Control. How to program the filter and heater and run different operational modes.
  • Diagnostics: Status Codes and Error Codes. Nicer models also have low/high Chemical Alerts and Service Reminders.
  • How to control different banks of spa jets, or water falls and air blowers or air intake valves.
  • How to work everything else: Spa lighting, sound system, ozonator, sanitizer system.


By this point in the manual most people naturally start to glaze over. I recommend coming back to it in a day or two with fresh eyes ~ because your spa maintenance is what you really need to learn fast – because it begins now! Maintenance items can include maintaining the surfaces, equipment, spa cover and also the water.


In general, most troubleshooting sections for spas and hot tubs are a bit thin, but complete enough for the average spa owner to check all the basic stuff, without getting in over their head. Most spa manufacturers would prefer that spas are serviced by trained mechanics, but will help you over the phone or by email if you try all of their suggestions (twice!) before calling.

  • Equipment Problem/Cause/Remedy tables
  • Flow Charts with Yes/No paths
  • Low water / No water flow from Spa Jets
  • Spa does not heat properly
  • Spa water is not clean


solana-owners-manual-coverSo you see – spa and hot tub owners manuals can be an invaluable resource to the spa owner. If you are looking for your old owner’s manual, and your spa is older than the 90’s – it is probably hard to find.

We have a huge list of links to spa owners manuals available, on a blog post we did last year, and updated – just now!


Happy Hot Tubbin’

Daniel Lara
Hot Tub Works


How to Shock a Hot Tub

February 1st, 2016 by

cloudy-spa-water-after-shockingWhat does it mean when we speak of shocking a hot tub? I like to say that my spa is shocked every time I remove my towel, but that’s just my little joke. 🙂

Spa shock is an oxidizer that is used to destroy organic contaminants that have been able to escape normal daily sanitation. Oxidation involves the transfer of electrons, and when hot tub water contaminants or pathogens are oxidized, they lose electrons, and quickly expire, or cease to exist.

Today’s blog post is all about shocking a spa or hot tub. What, how, when and why a spa or hot tub is shocked. A shocking topic to be sure!


What is Hot tub Shock?

Hot tub shocks are made from a powdered form of oxidizer, either a form of granular chlorine, non-chlorine potassium sulfate salts or liquid chlorine (bleach). When using a biguanide sanitizer system (Aqua Silk), the spa shock is made of liquid hydrogen peroxide, which can not be used in a bromine or chlorine treated spa/hot tub.

Why do I need to shock a hot tub?

There are 3 main reasons to shock a spa: 1. To destroy excessive contaminants in a hot tub after use by several people, 2. To reactivate bromide ions into active bromine, and 3. To kill algae, bacteria, viruses and pathogens that may escape your normal daily sanitation chemical.

How to shock a spa with bromine?

Trick question – you don’t shock a spa with bromine. There is no such thing as bromine shock, although many people confuse bromide ions with spa shock. Bromides (aka Bromine Boosters or Reserve) are used sparingly to boost the ‘bromide bank’, which is reactivated into bromine by using chlorine granules, or MPS (aka non-chlorine shock).

How to shock a spa with chlorine?

Chlorine granules are available in varying concentrations or strengths, so follow label instructions closely for proper dosage. For a 300 gallon spa, 0.7 oz of Chlorine Granules shaken over the water surface, will raise the chlorine level up to about 10 ppm. This should be done with a balanced pH (in the low range of 7.2-7.4), and with the circulation pump running on high to help distribute the shock quickly. Keep the spa cover open or removed for about 30 minutes after adding spa shock, to allow reaction gas to escape and prevent damage to the spa cover. The hot tub should not be used until the chlorine/bromine level drops back below 5 ppm.

How to shock a spa with bleach?

Regular household bleach (non-scented and without additives) can be used in a spa, but the pH level may rise as bleach has a very high pH of 13. For this reason many spa owners may find it easier to use dichlor (chlorine granules) or non-chlorine shock (MPS), which are more pH neutral. Testing the water with a chlorine test kit will determine the proper amount, but for a 300 gallon spa, 1 cup (8 oz) of 5% strength bleach will raise the level to 10 ppm.

How to shock a spa with non-chlorine shock?

Chlorine free shock, also known as MPS (or PPMS) is Potassium Monopersulfate, or Potassium Peroxymonosulfate, is a quick dissolving and powerful oxidizer that is popular for use in spas and hot tubs. It’s not measured with a regular spa test strip, so following dosage instructions is important. For example however, when shocking a 300 gallon spa, 1-2 oz. of non-chlorine shock is used, broadcast over the water surface, with the spa pump running. Like other types of spa shock – add after you use the hot tub, not before.

Is Hot Tub Shock Dangerous?

spa-and-hot-tub-shock-smIt depends if you are shocking with 110V or with 220V! Just another little joke, but seriously folks, Spa Shocks are dangerous – if mixed with any other chemical, or allowed to become moist, or contaminated with dirt or debris, it has the ability to produce noxious fumes, catch fire or explode.

Yes, spa shock can be extremely hazardous, and must be stored in a cool, dry location, safely out of the reach of children. Overdosing your spa or hot tub with shock may damage the finish, or the spa cover. And using the spa before allowing chlorine/bromine levels to subside can bleach swimsuits or cause skin irritation or breathing difficulties.

Always follow the label instructions closely for dosage and use instructions, and keep your spa oxidizers clean, cool and closed. Be safe with spa shock because – oxidants happen! 🙂



Gina Galvin
Hot Tub Works



Saltwater Hot Tub – Bromine or Chlorine

January 18th, 2016 by

saltwater-hot-tubs Before I write a post, I survey the ‘information landscape’ with a few keyword searches, to see what’s been written about the topic. There’s a lot of misinformation out there about saltwater hot tubs. Sounds very familiar, I heard the same discussions ten years ago about swimming pool salt water systems.

It smells like fear – fear of change, fear of losing bromine tablet sales, fear of the unknown. What really happens is that when a saltwater bromine or chlorine generator is installed, you won’t need to buy, store, transport or handle bromine tablets anymore.

You’ll still need other spa chemicals, because you still have to balance the pH, alkalinity and calcium hardness levels. You may still need to use clarifiers, enzymes or foam out. And, you’ll still need to test the water regularly, and clean and replace your spa filters. In short, you’ll still do everything you do now, with exception to adding bromine tablets or oxidizer to the hot tub.

Saltwater systems for hot tubs are not a miracle product, but it does have a few benefits over sanitizing with bromine tablets or bromides/oxidizer or chlorine.

  • Softer water due salts; sodium chloride (for chlorine) or sodium bromide (for bromine).
  • Fewer peaks and valleys of sanitation. With other methods, levels are less consistent.
  • No worry about checking and adding tablets or shock to reactivate bromine.


Water softness or hardness is in direct relation of how much calcium is in the water, or the calcium hardness measurement of the water. For spas and hot tubs, low calcium from soft water is not a good thing, but that’s not what I mean when I say that saltwater hot tubs have softer water.

What I really mean is that the water feels softer on your skin, it feels almost silky, slick, or oily. This is because of the salts in the water, similar to how adding bath salts or spa crystals to your spa or bath water makes the water feel more … luxurious? It’s also less drying to the skin, as opposed to using tablets or shock oxidizer.


peaks-and-valleysA salt chlorine or salt bromine system can maintain a very consistent level of sanitizer in the water, with digital controls to program an exact level of chlorine or bromine. When using bromine tablets, it’s harder to control the dissolution rate of the tablet. When the floater or brominator is first filled, more bromine will be released than when the tablets are almost gone. To control this problem, you will need to turn down the brominator dial (or the floater holes), and as the tablets dissolve, open it up more.

For bromine spas that don’t use tablets but use a shock (MPS or Dichlor) to activate bromide ions, turning them into bromine, the problem is even more pronounced. Immediately after adding the oxidizer, the bromine level can shoot up very high (peak), and then slowly drop back down to a low level (valley).


With a saltwater hot tub system, bromine or chlorine production is steady and controlled, and you don’t have worry about adding more sanitizer at the exact moment it runs out, or catching it before it runs out, or drops to near zero levels. However, keep in mind that inline saltwater chlorinators or saltwater brominators only make chlorine or bromine when the pump is running. The Saltron Mini and other drop-in types of salt cells are an exception to this, since they are not plumbed inline, but hang over the edge of the spa or hot tub. But if your spa pump is running daily, any type of salt system can create enough chlorine needed for daily disinfection.

A lot of people don’t know that a saltwater hot tub can be either bromine or chlorine. Add sodium chloride NaCl, regular table salt, and your salt cell will create chlorine. Add sodium bromide salts however, and your saltwater hot tub will be a bromine hot tub. Bromine is more stable than chlorine in high temperatures and in varying pH levels, and is considered a better sanitizer for hot tubs.

Hot Tub Salt Systems are not a miracle productSalt systems for spas allow you to make your own ‘locally sourced and organic’ chlorine or bromine, on-site. But that’s all it does – replacing bromine tablets or other means of sanitation. Not a miracle product – it won’t reduce spa maintenance by too much, but it does have at least three clear benefits over traditional methods.


Happy Hot Tubbin’

Daniel Lara
Hot Tub Works


Spa Chemical Dosage Charts

January 11th, 2016 by

trutest-strip-reader-spa-lgI’ve heard it said that “spas and hot tubs are not just small pools” – indeed, they are very small pools.

So small in fact, that the equivalent of 4 people in a spa is like having 200 people in a pool! Wacky things happen to water chemistry when even one person is using the spa or hot tub – pH jumps, alkalinity drops, and sanitizer is pummeled.

But you know this – if you take care of a spa or hot tub, regular water testing confirms irregular water chemistry, in most hot tubs. And you know how to take care of it too, a little bit of this, a little bit of that… and your spa water is balanced once again.

Today’s post is designed to be a resource for the busy spa owner, a printable reference sheet of how much spa chemical to add, for an expected result. Print Out the image below and tape it inside the spa cabinet door, or on the lid of your chemical box. Plastic sleeves or report binders will keep it dry and readable.

OverDosing the Spa is very common. Measure spa adjustment chemicals carefully, using 1/8 cup (1 oz) or 1/4 cup (2 oz) kitchen measuring cups. Another useful tool, the kitchen tablespoon is 1/2 ounce, and the tablespoon is 1/6 ounce, or 0.17 oz. Add small amounts and test again after an hour or so of circulation. Keep a log book of chemical test strip readings and adjustment chemicals used – I know, sounds geeky – but it can be very helpful in getting to know your spa’s chemical personality, and how it reacts to people chemistry.

Not sure How Many Gallons is in your Spa? Mathematical formulas exist, but can wrongly estimate the gallons in a portable spa, due to the varied internal seats and shapes. The best way to calculate the number of gallons in a spa is to time exactly how many seconds it takes to fill the entire spa using a stopwatch. Then time the exact amount of time it takes to fill in five gallon bucket, in seconds. Divide Spa Fill time by bucket fill time to determine spa capacity. For example, if it takes 1800 seconds (30 minutes) to fill your spa, and 30 seconds to fill a 5 gallon bucket, then… 1800 ÷ 30 = 60 buckets x 5 gallons = 300 gallons. Another way to find out is to consult the owner’s manual, or search online by make/model – if the spa was built by a known manufacturer.

Spa Chemical Dosage Charts

Print out this chart and place it near your spa chemical storage area, for quick reference. Write or circle the number of gallons in your spa or hot tub.



One more tip: Always add one chemical at a time, allowing 15 minutes of circulation before adding other spa chemicals. Adding chemicals right on top of each other can affect the effect!


– Jack