Free Shipping on all Spa Covers and orders over $100 Black Friday Deals!
Sunday - Saturday
7am - 7pm CST

Archive for the ‘spa chemicals’ Category

Is Your Hot Tub a Chemical Soup?

October 12th, 2015 by

chemical-soup-hot-tubsThe first question about the so-called “Chemical Free Hot Tub” is “What does it Mean to be Green?” The second question is “Can it be done?”; a chemical-free hot tub, that is.

When you speak of eco-friendly spas and hot tubs, you may be talking about saving energy, saving water, or preventing pollution.

It’s that last part I want to discuss today – preventing pollution of local watershed, while enjoying a hot tub without unnecessary and unnatural chemicals.


What Does it Mean to be Green?

There are several categories of spa and hot tub chemicals that are considered “Green”, most made of natural ingredients and harmless to plants and animals.

natural-spa-chemicals--Spa Enzymes: Enzymes are all-natural, microscopic organisms that eat oil and organics for breakfast, lunch and dinner. Reduces the amount of sanitizers needed, and helps filtration by removing oily gunk.

Citrus Cleaners: When cleaning a spa, to remove water line marks or polish up the shell, be careful not to use household cleaners that contain harsh chemicals, but instead use a citrus or vinegar solution.

Natural Clarifiers: Companies like SeaKlear have used crab shells for years as a natural clarifier for pools and spas. Natural polymers help your filter by coagulating smaller particles into easily filterable clumps.

There are also several “Alternative” purifiers, or systems that can supplement your bromine or chlorine residual, but aren’t complete sanitizers – they can’t usually do it all.

Ozone: Ozone generators create small amounts of the O³ molecule, which is very powerful, and kills anything that can exist in water. But, the distribution method can’t get the gas in contact with everything.

Minerals: Even the Ancients knew the power of copper and silver to purify water; and for a spa it’s super easy to add minerals with a Spa Mineral Stick, there are many brands available.

UV systems: The Ancients also knew of the power of sunlight to kill algae and mold. When water is bathed in UV light, most pathogens, bacteria and viruses will die – but not everything.

In addition to sanitizing the water daily and continuously, a hot tub needs periodic oxidation, or spa shock.

Is a Chemical Free Hot Tub Possible?

You can reduce reliance on chlorine and bromine by using supplemental sanitizers like minerals or ozone or UV systems. Use non-chlorine shock (MPS), if you want to be chlorine-free.

But, you will still need to test the water and add balancing chemicals, to lower pH, or raise alkalinity and calcium levels, for example.

Unless you drained the water every time you use the hot tub (not very Green), you will need to maintain balanced water (pH, alkalinity, calcium), as well as daily disinfection to sanitize, and regular shocking to oxidize the water.

However – if you want to operate a spa or hot tub without bromine or chlorine, it is possible.

For low-use hot tubs, an ozone or UV system AND a mineral stick will keep the water clear. Shock (oxidize) the water with MPS after each use (very important). Filter the spa water for at least 6 hours daily, and buy a new spa filter cartridge every 12 months (very important). Adding a natural clarifier or enzymes to the spa can also aid in reducing the amount of sanitizer and oxidizer needed.

Chemical Soup Hot Tubs?

With supplemental sanitizers and careful water balancing, you don’t need to add 9 kinds of spa chemicals to maintain clear and healthy water.

Instead, over-filter the water and combine natural spa chemicals and alternative purifiers for daily disinfection, and oxidize with MPS after each use, or weekly.


Happy Hot Tubbin’

Daniel Lara
Hot Tub Works





Most Popular Hot Tub Chemicals

October 5th, 2015 by



Going over sales spreadsheets is one of my primary jobs here at hottubworks. Sales trends are interesting to watch, and important to know – so we can meet seasonal demand.

Knowing the most popular hot tub chemicals can also be useful to the spa owner! Don’t get left behind – here’s the spa chemicals that your neighbors buy most frequently.

This isn’t just a unit sales contest, to be fair we also used velocity and frequency, to produce a more accurate list of the most popular spa chemicals – by category. “May I have the Envelope Please….”


aquachek-spa-test-stripsAquaChek 6-In-1 Test Strips: We have a lot of Test Strips to choose one, but the 6-in-1 is usually the top seller in the category, seconded by the TruTest digital test strips. The 6-in-1 will test for everything you need bromine/chlorine, and also Free Chlorine, which lets you know if there are high levels of bromamines or chloramines in the water. Aside from total, free and combined sanitizer – this strip also checks your water balance levels of calcium hardness, total alkalinity and pH, all on one test strip.


spa-frog-floaterSPA FROG Floating System: Nature2 or the other mineral sticks are popular, but for an all-in-one solution, you can’t beat the Spa Frog, which has a bromine cartridge and mineral cartridge that fit into a cute little floating dispenser. The bromine cartridge (yellow) has an adjustable openings so you can set the amount that is released, and the mineral cartridge natural filters the water as it passes through the mineral cartridge (green). With just a few pounds of MPS on hand, this may be all you need to keep your spa clean! 


brom-booster-twoHTW Brom Booster: This product is popular for the bromine spa or hot tub (which is about 60% of spa users, by my estimate). When you drain the hot tub, as you should do every 3-4 months, you lose the “bank” of bromide ions in the water. It takes weeks and weeks for enough bromine tablets to dissolve to produce enough bromides in the water, so that bromine can be created. Complicated, just add a capful of Brom Booster after draining the spa , or significant dilution, to “build the bromide bank” again.


leisure-time-spa-56Leisure Time Spa 56 Chlorinating Granules: 56% blend is pH neutral and more stable in hot water than other types of granular chlorine. Don’t ever use pool shock in your hot tub, it’s too strong and evaporates within hours. Spa 56 can be used for regular chlorination or weekly spa shocking, and is a great way to reactivate bromides (see above) in a bromine spa. Just a capful of chlorinating granules can bring levels up quick, or be used as an effective way to control algae and biofilm.


leisure-time-defenderLeisure Time Spa Defender: A blend of organic polymers that locks up minerals like calcium, phosphorous, sodium, which can cause cloudy water and scale – and scale is bad for spas. If you live in a hard water area (and nearly 50% of the country does, by my estimate), you want to control the minerals by using a sequestering agent like Spa Defender. Natural formula protects your filter, heater and beautiful spa surfaces, which is why it’s one of our 10 most popular hot tub chemicals!


rendevous-natural-clearRendezvous Natural Clear for Spas:
Natural Clear is an enzyme that removes scum lines and foam by digesting oils, lotions, make-up, and other oily gunk that we bring into our spas and hot tubs. Helps control biofilm development by attacking the outer layers that protect the colony. Just 1 oz every other week removes oils from the water, which protects your filter cartridge, and keeps your spa and spa water looking good. This product is a must for high-use hot tubs or spas with small-ish spa filters.


culator-spa-pakCuLator Metal & Stain Spa Pak:
This is the only product that actually removes metals from your spa or hot tub water. Other chemicals just lock-up the chemicals with strong bonds, but CuLator actually absorbs metals in the safe and non-toxic pouch. Drop the Spa Pak into your skimmer or filter, it attracts all heavy metals, like iron, copper, manganese, cobalt, lead and other stain-causing minerals.


spa-alkalinity-increaserHTW Spa Alkalinity Increaser:
Your water’s Alkalinity is what keeps the pH in check – not enough Alkalinity and the pH level will bounce around a lot. In most hot tubs and spas, pH tends to rise when used regularly. That’s because all the oils, lotions, dirt, dead skin and other unmentionables that we bring into the spa – tend to raise the pH level. Spa Owners lower the pH regularly; which also lowers the Alkalinity over time. Keep Alkalinity above 80 ppm.


htw-spa-ph-minusHTW Spa pH Minus: And here’s the other part of the equation, the reason the Alkalinity level tends to drop over time, is that pH minus, while lowering pH very effectively, also lowers Alkalinity somewhat. Each time you add a half capful of pH Down into the spa, the Alkalinity takes a little hit. What are you gonna do? You have to keep the pH in check, or everything else will quickly go out of whack. Use pH Minus as needed to keep pH in the 7.4-7.6 range, so that your sanitizer is most potent, and stains and scale can be prevented.


leisure-time-filter-cleanLTO Leisure Time Spa Filter Clean – Overnight Soak: To really get your spa filter cartridge clean, you have to soak it in a solution. A good, complete spray with the hose is still needed, but afterwards, soak your spa or hot tub filter cartridge in a solution of Spa Filter Clean. Double action formula removes greasy deposits as well as scale, dissolving and lifting them from the cartridge fabric. After an overnight soak, hose off and then allow it to dry fully, to kill any bacteria. This is why it’s good to have a spare spa filter cartridge.



Back to my spreadsheets! I’m sure you can find many of these in your spa chemical storage. I use most of these products above in my own spa, and can attest to their usefulness!


Carolyn Mosby
Hot Tub Works


CDC Report on Recreational Water Illness

August 6th, 2015 by

CBS-News-Sick-SwimThe media is all abuzz about a recent report from the Centers for Disease Control that shows that Recreational Water Illness (RWI’s) are on the rise in American pools and spas.

Since 2010, a National Outbreak Notification System (NORS) has been established that allows public pool and spa operators to voluntarily report any outbreak of water related illness.

For the 2011-2012 reporting period, NORS has documented 1300 RWI’s in public pools and spas, with 75 hospitalizations and one reported death. Over half of the illnesses were caused by Cryptosporidium, or Crypto as it is more ominously known. Pseudomonas accounted for the majority of other illnesses.

What Causes Recreational Water Illness?

Where does it come from – it comes from bathers! Mostly from unwashed behinds, or from “accidental fecal release” of those infected with the parasite. Very tiny amounts of poop from an infected person can infect others – who accidentally drink the water, or absorb it into their eyes or open sores.

Crypto and other pathogens are not only found in human and animal stools, but can also be found in soil, food and on unclean surfaces. It can enter the spa in more ways than just the backside of an infected person. The CDC estimates that 750,000 Americans are infected each year with Cryptosporidium.


Why Doesn’t Chlorine Kill Crypto?

DEL Ozone MCD-50, it's what I use on my spa

Usually it does, but cryptosporidium has the ability to cloak itself from low levels (1-3 ppm) of chlorine or bromine. And if the pool or spa has high pH and/or a high level of chloramines – it becomes a very weak sanitizer, not strong enough to kill all pathogens. For this reason, the CDC recommends supplemental sanitation by Ozone or UV light systems, for pools or spas that have a high risk or history of infection.


Reducing Recreational Water Illness Risks

  • Shower with soap before using a pool or spa
  • Do not use a pool or spa if you’ve had recent diarrhea
  • Maintain spa bromine at 3-5 ppm, and use Ozone or UV
  • Balance the pH and shock the spa after each use
  • Keep your head above water and don’t drink the water
  • Limit spa sessions to 15 minutes


Is Your Hot Tub – Infected with Crypto?

bacteria-in-spasIt could happen, all it takes is one infected person who hasn’t showered to infect a spa or hot tub. The data collected by the CDC is entirely gathered from Public pools and spas, not residential – but a residential spa can become infected just as easily – all you need is an unclean bather, insufficient sanitation and poor water balance.

But I don’t mean to scare you – I would estimate that 90% of well-maintained residential spas are pathogen-free. When in doubt, shock the spa or change the water!


- Jack





Hot Tub Water Test: Like a Boss!

July 27th, 2015 by

TESTING-HOT-TUB-WATER-LIKE-A-BOSSTesting hot tub water regularly is important to avoid peaks and valleys of sanitation and water balance. Testing everyday is not needed unless your spa is used on a daily basis. Test your water 2-3 times per week, or more often if the spa is used frequently.

For years I used Test Strips to test my hot tub water, that’s what the Hot Tub Guyz (where I bought my first spa) told me to use. They even gave me a free bottle in a starter kit.

When I started working here at HotTubWorks – I was immediately shown a better way of testing hot tub water. It was in a product meeting, when someone asked when were going to start offering a real test kit for sale. I find out that we sell 12 different test strips for spa water, but we don’t have the “pool” test kit that everyone around the office uses.

It is now years later, and guess what – we still don’t sell the test kit which we all agree is the very best. Maybe this post will embarrass them into action! You can’t really rely on test strips for spa water – when you are only working with 300-500 gallons, it’s crucial to be accurate, or you can easily underdose or overdose.

Good Spa and Hot Tub Water Test

Spa-and-hot-tub-test-strips-travel-packSpa test strips are made to work with hot water, and are ‘calibrated’ especially for spas (whatever that means), but the wide range and hard to determine color matching makes them less accurate or reliable, when compared to other types of hot tub water testing.


Better Spa and Hot Tub Water Test

digital-strip-testerA better way to test spa water is to not abandon test strips, but to remove the human interpretation from the equation. No offense, but your eyesight and color matching skills aren’t what they used to be (mine neither!). The AquaChek Digital Strip Reader analyzes the test strip from 16 Million colors, and improves accuracy of test strip use immensely.


Best Spa and Hot Tub Water Test

The best way to test hot tub or spa water (if accuracy is important to you), is to use a liquid drop style, pool test kit. The one we all use here on our own hot tubs is usually, the K-2006, although some people have the K-2106. Both test kits are by Taylor, a well respected source.

Titration test kits are different, and here’s why. Take a water sample in a test vial and add the reagent. Then add an indicator solution, dropwise, or drop by drop, counting the drops until you achieve a solid color change (from red to blue for example). Multiply the number of drops x 10, and you have your calcium and alkalinity reading, accurate to within 5 ppm.


Yes it takes longer to do a titration test, but not much longer. You can do a full battery of tests, Bromine, pH, Alkalinity and Hardness in under 5 minutes. If your hot tub calcium or alkalinity is low, refer to the charts in the booklet, which tell you exactly how much adjustment chemical to add.

If your hot tub pH is high or low, you can do a titration test on the pH sample, adding Acid demand or Base demand reagents, dropwise, until your desired pH color is reached.

For measuring Bromine, and Bromamines, nothing beats a titration test. Traditional test kits have you add DPD reagent #1, 2 and 3 to the water sample vial, and compare the colors. FAS-DPD uses titration (drop counting) to most accurately determine chlorine or bromine readings to within 0.5 ppm.

You can buy the Taylor K-2006 test kit online - just not at Hot Tub Works! The box label reads Chlorine, but it tests for both Chlorine and Bromine. You won’t need the Cyanuric Acid test, unless you have an outdoor and uncovered spa.


So, if you want to be accurate with hot tub water testing (and who doesn’t?), get the best hot tub water test available, and toss away your test strips for good!


Gina Galvin
Hot Tub Works



Test & Balance Hot Tub Water

July 6th, 2015 by

filling-the-spa-or-hot-tubI know some people who claim to have “perfect” spa water right out of the tap – “I don’t even need to test it”, they say.

That may be true for some people, but for the majority of spa owners, the water from the tap or hose may have very low levels of calcium, alkalinity, pH. Well water can also contain loads of minerals and metals, and city water can be full of chloramines and other water treatment byproducts.

When filling a spa after draining, you start fresh again, with “New” water. What follows is a step-by-step on how to test and balance spa fill water, to make it perfect for hot tubbin’.


1. Pre-Filter the Water

For well water, this is a must. “Yeah, but my well water goes thru filters and a conditioning system” you may say, but did you know that most outdoor hose spigots are not connected to a home water treatment system? Only kitchen, bath and laundry. You can fill a hot tub from a utility sink, if you have a faucet adapter, or you can just screw a pre-filter onto the end of the garden hose. A spa pre-filter traps minerals, metals, chloramines, bacteria and hundreds of other junk that you don’t want in your spa water.

For city water too, a pre-filter will remove pathogens and impurities (remember that city water is partially made up of raw sewage), and pre-filters remove chloramines. It also removes dissolved solids, down to 1 micron, which is quite small and invisible. Even if your tap water looks good and smells good, filtering it as you fill the hot tub will improve the water quality – and make your spa water easier to manage.

2. Check Calcium Hardness

The first step after refilling a spa or hot tub is to check the hardness of the water. Test strips can be used, but a liquid test kit is much more accurate. For hot water spas and hot tubs, water that is too soft can foam easily, and also makes the water aggressive and corrosive to pump seals and o-rings, and shiny spa finishes. Spa water that is too hot can cloud easily, and deposit scale around fittings and at the water line. For spa water that is too soft, (under 200 ppm), add Calcium Increaser to raise the level, making the water “harder”. For water that is already hard (over 400 ppm), common in many parts of the country, well – we don’t have a chemical to lower Calcium Hardness, but using the Pre-Filter can lower total hardness by several hundred ppm. Spa hardness is best in the 180-220 ppm range.

3. Check pH & Alkalinity

pH and Alkalinity are close cousins, as outlined in a recent post. Total Alkalinity measures the carbonates and bicarbonates in the water, which act as a buffer to pH change. If your pH “bounces” or changes easily, you likely have low alkalinity. If your pH is resistant to change, you likely have high alkalinity. For spa water with low alkalinity (under 80 ppm), add Alkalinity Increaser to raise the level. For water with high Alkalinity (over 150 ppm), use the pH Down chemical or other acid, to lower the level – which will also lower your pH level somewhat. After filling the spa, adjust alkalinity to the 80-120 ppm range. Spa pH should be in the 7.2 – 7.6 range. A proper pH helps bromine and chlorine work their best, and helps prevent damage to seals, o-rings and surfaces. If your tested pH is too high, add an acid (pH Down), and when it’s too low, add a base (pH Up).

4. Add Bromide & Bromine

One disadvantage to dumping the spa water every 3-4 months is that you lose your bank of bromide ions. Bromine, unlike chlorine, takes a while to build up a “bank” of bromide ions. It can take several weeks of waiting for bromine tablets to dissolve, shocking every few days – or the faster recommended method is to add some Bromine Booster to the spa. Just a few capfuls of Brom Booster brings up the level of bromide ions, so that you can see some results when you test the bromine level. After adding bromides to the spa, fill the spa floater or brominator with half a dozen 1″ bromine tablets. Test the bromine level over the next few days, your spa may need slightly fewer (4) or slightly more (8) bromine tablets, to register a consistent 3-4 ppm bromine reading.

>>> After all of that work, you’re ready for a dip in the tub! Here’s one more Tip: write down exact quantities of what you need to add to fresh fill water – chances are, your source water will stay fairly stable and consistent in it’s chemical balance, so write down exactly what you need to add to make it perfect for hot tubbin’.


Happy Hot Tubbin’

Daniel Lara
Hot Tub Works




What Chemicals are Needed for a Hot Tub?

June 29th, 2015 by

hot-tub-chemistry-start-upSpa chemistry is something that needn’t make you anxious, and once you get the hang of it, most hot tubs will exhibit something of it’s own chemical personality, one that you will get to know well.

What I mean is, you will get to know when it needs more of something, and if you were to really geek out, and keep a spa chemical log, (like me!), you can see water balance trends over time.

For instance, my hot tub is tested 2-3 times per week, and I record my readings in a little book. If I flip back thru, I can see that about every 3 weeks I lower the pH, and about every 6 weeks I need to raise the alkalinity. I also see that on average, I use about 14 bromine tablets and 9 oz of spa shock every month. Good to know.

break-it-downBut you didn’t come here to hear stories about my hot tub – you came here to find out exactly what chemicals are needed to maintain a hot tub? What do you need to buy? And, what do you Really Need, and what is more… Optional.

There are a half-a-dozen different categories of hot tub chemicals, each with about a half-a-dozen different chemicals, from about a half-a-dozen different brands. And that’s what makes hot tub chemicals seem so confusing; let’s see if we can’t Break it Down into smaller chunks…



  • Test Strips or Test Kit – test spa water 2-3x per week
  • Bromine tablets – for continuous sanitation
  • Bromine Booster – Raises bromide levels after draining
  • Spa Shock – regular super-sanitation, weekly
  • Spa pH & Alkalinity Balancers – as needed


  • Spa Calcium Increaser – increases water hardness
  • Hot Tub Clarifiers – coagulates small particles for easier filtering
  • Spa Cartridge Cleaner – get a second year with a deep cleaning
  • Mineral Purifier - purifies with copper and silver ions
  • Spa Polish / Spa Cleaner – clean and polish the spa shell


  • Defoamer – for foamy spa water
  • Metal Remover – or metal stain removers
  • Spa Cover Cleaner – and conditioner
  • Jet Clean – biofilm cleaners
  • Leak Seal – seals up weeps, seeps, leaks6-month Bromine Spa Care Kit

A simple and more economical way to stock up on the basic spa care chemicals is to buy one of our 6 month spa care kits. We have 8 different spa chemical kits available from mild to wild, in your choice of bromine, chlorine or Nature2 mineral sanitation.

As a bare minimum, you have to have chemicals to test and balance the pH, continuously sanitize the water, and regularly oxidize (shock) the spa. An ozonator or mineral purifier by itself can’t do the job alone; in addition, put bromine tablets into a spa floater, and then add a few capfuls of spa shock after using the spa.

Also important is to test and maintain the pH and Alkalinity, so it doesn’t get too high or too low. Use test strips to test the water, and then add a pH or alkalinity increaser or decreaser, if pH has strayed outside of 7.4-7.6, or alkalinity is below or above the range of 80-120 ppm.


Happy Hot Tubbin’

Daniel Lara
Hot Tub Works


Hot Tub & Spa Safety Products & Practices

June 8th, 2015 by

toddler-in-a-hottub-from-here-to-maternity-dot-comSafety products for spas and hot tubs? If you’re wondering how to child-proof your hot tub or spa, it’s a question that we get a lot here ~ new parents asking how to keep toddlers and children safe around hot tubs.

Not as common as pool safety products, which have several types of safety covers and dozens of pool alarm systems, but there are several practices and products that you can use to elevate your hot tub safety.

Today’s blog is a list of spa safety products and some hot tub safety tips to make a spa safer for children to be around.



PLEASE-LOCK-THE-SPAEvery hot tub should have a spa cover in good condition, and cover straps with clips in at least 4 locations. If your cover begins to take on water, or puddle in the middle, buy a new spa cover, or replace the foam panel inserts. The small cover clips don’t look like much protection, but they’re almost impossible for small hands to operate. For more protection use our heavy duty spa straps, meant for protection from high winds, but they also function as another layer of protection.


lock_icon_image_150_wht_16460Most spa cabinet doors open fairly easily, and many have a magnetic latch that prevents the system from starting if the door is ajar, but very few people I know lock their spa cabinet door. All you need is a latch and padlock from a hardware store, and a screwdriver to install it. This will protect small people (who are always drawn to small doors) from getting under the spa, into the equipment bay, where electrical hazards (and other hazards) exist.


door-alarms-by-poolguardAnother good option to secure the spa is to use door alarms for any door or window that leads to the hot tub area. Like the pool fencing below, door alarms are a pool product that is easily adapted for increased hot tub safety. They install easily in minutes, and run off a 9V battery, like a smoke detector. Pass thru button allows adults to enter through either direction without setting off the alarm. Gate alarms can also be used, mounted on fence posts for backyard gates. They operate the same way as door alarms, but have attachments for different fence posts.


In most areas, a suitable fence is required to install a hot tub. However, I know that there are many spas and hot tubs that don’t have a fence anywhere nearby. A good fence around the backyard will protect your neighbors and local wildlife from potential catastrophe, but what about children inside the house? In many homes, one door on the back of the house is all that separates a spa or hot tub. safety-mesh-pool-fencingAn easy solution is to install removable pool safety fencing around the spa, to create a secondary barrier to the hot tub. Mesh pool fence panels are 10 ft long, and install into wood or concrete; removes easily when using the spa, or when children are grown.


spa-chemical-lockerWe’ve talked before about safe spa chemical storage, here and also here, and shown you many ways to creatively and safely store spa chemicals. Tips for safe spa chemical storage won’t include storing them in the hideaway steps, or underneath the spa. Just like other household chemicals, hot tub chemicals need to be stored safely out of reach of children. A sturdy, locking chest or box with a latch is most suitable. Simply storing them out of sight, or out of reach (on a high shelf for instance), may not be the best place to keep your spa chemicals.


Some of the most unsafe spa designs is an inground or sunken spa. This is because they are at ground level and are often left uncovered or the cover is not anchored into the ground. For an inground spa or hot tub, you can secure the cover clips into the floor, just use a masonry or tile drill bit and use anchor sockets. indoor-inground-spaI also recommend the thickest and strongest spa covers for inground spas, 6″ tapering to 4″, to protect the spa cover from dancing kids, falling adults and sleeping dogs. It is common to use a flat cover indoors, but these are not very strong or energy efficient.


  • Always put the spa cover back on and latch the clips after use.
  • Keep the spa chemicals and the spa equipment safely locked up.
  • Consider additional layers of protection, like alarms and fencing.

single_eye_movement_150_wht_9341I applaud you for childproofing a hot tub, or making your spa safer, and commend your excellent research that lead you to my little ‘ol blog post! Whether you are protecting kids or grandkids, remember that there is no substitute for supervision! Keep a watchful eye on the children!


Carolyn Mosby
Hot Tub Works





pH & Alkalinity in a Hot Tub or Spa

June 1st, 2015 by

digital-strip-testerToday’s post is hopefully a simple post, although it can be a complicated topic. pH and Alkalinity are close cousins in water chemistry, each affecting and affected by, the other.

pH is a measurement of how acidic (below 7.0) or basic (above 7.0) – your hot tub water is. Alkalinity is a measurement of the amount of carbonates and bicarbonates in the water, which act as a buffer to help stabilize pH.

When pH is LOW (below 7.0), the water becomes corrosive to seals, gaskets and plastics. When pH is HIGH, the water can produce scale, leading to cloudy spa water or deposits of calcium on surfaces and inside pipes.

Lower pH by adding Spa pH decreaser, or sodium bisulfate.
Raise pH by adding Spa pH increaser, or soda ash.

When Alkalinity is LOW, this causes pH to “bounce” or change easily – you may raise the pH, but it only lasts for a few hours. When Alkalinity is HIGH, this makes it hard to adjust pH in the first place, it makes pH very resistant to change.

Lower Alkalinty by adding Spa pH decreaser, or sodium bisulfate.
Raise Alkalinity by adding Spa Alkalinity increaser, or sodium bicarbonate.

The problem is… trying to adjust alkalinity without affecting pH, or vice versa. Fact is, you can’t – since they are both so closely related – but there are some tricks up my sleeve.

  • To Lower Alkalinity more than pH, add the pH decreaser with the spa pump off
  • To Lower pH more than Alkalinity, add the pH decreaser with the spa pump on
  • To Raise Alkalinity more than pH, use Alkalinity Increaser, with the spa pump off
  • To raise pH more than Alkalinity, use pH Increaser, with the spa pump on

Another problem is… overdosing the spa or hot tub, and swinging the pH and Alkalinity far to the other extreme. Know your hot tub size in gallons, and refer to the label for dosage per 100 gallons.snake-oil-salesman-sm

Dosage is almost always just a capful or two, a few ounces – so be careful not to over-shoot the mark! Add a small amount and retest the water after 30 minutes, and if needed, re-dose again.

When lowering alkalinity, you may have to raise the pH again afterwards, just slightly, which may also raise your alkalinity again just slightly. In some cases, where alkalinity has drifted very high, over 150 ppm – you may need to make many adjustments – sort of a two steps forward, one step back kind of thing…

TIP: When buying pH and Alkalinity adjustment products for your spa – there’s no need to overspend. We have all of the major spa chemical brands, and also a lower priced house brand of spa pH and alkalinity chemicals.

TIP: Don’t use Pool Chemicals in your Hot Tub. Chemically, pH and alkalinity adjustment chemicals are the same, but the labeling is for a pool 100x larger, which makes it quite easy to over or under dose, even if you are good at math!

Keep at it! It’s important to have correct spa pH and alkalinity, both for protection of spa equipment and surfaces, and so that your sanitizer works most effectively.


Happy Hot Tubbin;’

Daniel Lara
Hot Tub Works


Cloudy Hot Tub After Shocking

May 28th, 2015 by

cloudy-spa-water-after-shockingI once asked Jack how he shocks his hot tub, and he said, and I quote “I take off my towel – that really shocks my hot tub!

Cloudy spa water immediately after shocking your spa is almost considered normal – there’s a lot of chemical reactions going on! But, clear water should return to a spa within a few hours.

However, when adding just ounces of a spa shock makes the water cloudy, there are other things going on; here’s a few places to look for the cause(s) of cloudy hot tub water after shocking.


Swimming Pool Shock

Using pool shock will almost always make your spa or hot tub cloudy. It’s not as fine or re-fined, meaning the particles are much larger, and they don’t dissolve right away. It also is loaded with calcium, which can be a problem if you’re in a hard water part of the country. If you want to use chlorine shock, use Spa 56 chlorinating compound, especially formulated for hot tubs, but don’t use pool shock in a spa or hot tub.

High pH & Alkalinity

Before you shock a spa, it’s always best to check your pH and Alkalinity. Especially if you shock after using the spa; adding a few sweaty bodies into your hot tub definitely spikes the pH with higher alkalinity levels, and a strong shock treatment can knock carbonates and bicarbonates out of solution, making spa water cloudy. Keep some spa pH decreaser on hand, you can use it for lowering both pH and alkalinity.

Hard Water Hot Tub

My water comes out of the tap here at 450 ppm of Calcium Hardness, which is high but not as high as some people in nearby desert areas or on a well. When your spa water is hard, that means it has a lot of dissolved calcium in it. Spas and hot tubs operate best around 200 ppm, and when there is more than that – it can come out of solution as visible scale. Especially if your spa pH is high, and you also have high calcium hardness, shocking the spa can make the water cloudy. To prevent this problem, fill your spa with water that has gone thru the water softening tanks, or use a Pre-Filter on your garden hose, to reduce total hardness levels.

Lotions & Potions

Once I caught my (ex) boyfriend with 3 smelly soccer friends, sitting in the tub after a Sunday match. After their hour long soak, I went to put the cover back on (uh, yeah…), and the water looked funky, so I added some spa shock and it went cloudy. Why? Because of all of the oils, sweat, dirt and who knows what else they washed into my hot tub (gross).

woman-in-robeAnd ladies, we are also not without blame ~ skin lotions, make-up, hair products, deodorant – it all washes off into the tub. And spa shocks don’t do very well with oily gunk, they have trouble breaking it down and this can turn your hot tub cloudy after shocking. So, keep your spa as clean as possible by showering before using, or at least be fairly clean, and keep your hair up.

I have a ritual before using the spa, which is usually in the evening. First, I spend 20 minutes removing make-up and showering. Then I saunter to the pool deck in my robe and hair wrapped up in a towel, (just like a real spa resort).

And unlike Jack, who says he shocks his spa by disrobing, my spa is shocked after I’ve enjoyed a long leisurely soak. I dip a test strip to double check pH and alkalinity, and shake in 2 capfuls of Zodiac Cense, a non-chlorine spa shock.



Gina Galvin
Hot Tub Works


Spa and Hot Tub Water Color Problems

April 30th, 2015 by

color-wheelWe’ve all been there before, when you lift the spa cover to discover a color other than clear blue. Hot tub water can be all colors of the rainbow when conditions aren’t right. Yellow, brown, green, white, and any shade in between.

Today’s topic is how to identify and troubleshoot colored spa water, to restore your beautiful blue spa water. It doesn’t matter what type of spa or hot tub you have, or even if your tub is as big as a pool, you can use these tips to fix colored hot tub water.

After you’ve spent several months (or years!) taking care of your spa – your trained eye can tell right away when something’s not right. A bit less sparkly and translucent, dull and dirty looking. Or one of these strange spa water colors ~


green-hot-tub-waterWhen your spa has a shade of green, one may immediately think of algae, and if your sanitizer has been low, or your filter cartridge dirty, it very well could be algae. Touch the sides of the spa, and if it feels slimy, you can bet you have a small algae bloom on your hands. Algae can grow even under a spa cover, in the dark, and in hot water. To treat a hot tub for algae, check and balance the pH and alkalinity, and add a shock treatment. After filtering out dead algae, it’s always recommended to replace the spa cartridge with new.

Green hot tub water can also be from a mineral we know as copper. It can enter the water from copper pipes carrying fill water, or from natural well water. It can also come from copper heat exchangers used in gas fired heaters, or could come from using copper pool algaecide in a spa (not recommended). This is the same copper that can turn a swimmer’s hair green – but the water can be clear and bright green, without slime on the surfaces. Remove copper from hot tub water with CuLator.


yellow-hot-tub-waterYellow algae is a particularly resistant type of algae that can exist in a dark heated hot tub, even in the presence of normal bromine or chlorine levels. It seeks out small out of the way crevices, and when in full bloom, will deposit itself as sheets across the spa surfaces. Treatment for yellow algae is to use a very high level of chlorine spa shock. Balance the water first, and turn off the heater before shocking the spa. Allow the water to circulate for several hours, with the cover removed. If the level drops to zero within 24 hours, shock the spa again, until it holds the chlorine level. After this shock treatment, drain and scrub the spa, bleach wash the spa cover and replace the spa filter with a new cartridge.

Yellow hot tub water can also come from an excess of Pollen in the springtime, especially if you have left the spa cover for some time, or iron oxides in well water can impart a yellowish color to the water, especially if the spa turned yellow after shocking. If you are on well water, use a pre-filter to remove all minerals from your fill water. Finally, if your bromine level is extremely high, the water can take on a yellow-red color, especially in the presence of low pH. Don’t enter a spa if the bromine residual is over 5 ppm.


brown-hot-tub-waterBrown water is not the most appetizing hot tub water color, and if your spa suddenly turned brown – the color of tea, you can once again usually find the problem to be high levels of minerals, namely iron oxide. This may occur within hours after shocking the spa, or making big pH adjustments. The filter cartridge should remove some of it, but to clear it up faster, you can force it back into solution with a sequestering agent like Metal Gon.

Brown spa water also occurs from contaminated fill water, and during dry hot periods, some municipal water supplies begin scraping the bottom of the barrel, which adds a lot of particulate matter to the water supply. You can combat this by using a Pre-Filter on your hose when you fill the spa, to remove even microscopic particles from your fill water.


white-hot-tub-waterMilky hot tub water, so cloudy that the water appears white can come from many causes. High calcium or alkalinity, or ineffective filtering or pumping, or air in the system causing micro-bubbles – all can make hot tub water turn white-ish. Contaminants from body lotions, cosmetics and hair products can also change the water color from blue to white. If your spa has cloudy water, here’s a blog post with 10 reasons why.

White hot tub water can also be infected with white mold, a type of bacteria that grows in small clumps and clusters. In spas that have not been maintained properly, this type of slime can be difficult to remove, but can be treated effectively with raising chlorine level to 30 ppm, running the spa for several hours and then draining. Replace the spa filter, and rinse all removable items like spa pillows, nets, baskets and thermometer in a strong bleach solution. Use a biofilm remover like Jet Clean to clean out the pipes.


pink-hot-tub-waterPink algae is a close cousin of white water mold discussed above. Not actually an algae, it’s a form of bacteria, although it displays characteristics of an algae.  Pink spa water is not a very common color for spa water, and pink algae won’t actually color the spa water pink, except in very mature colonies. Treatment for pink algae is similar to white mold above. It’s not easy to eradicate, as it is able to tuck away cells that are difficult to reach – but it can be eradicated, by hitting it hard with shock (over 30 ppm), and using a purge product to clean the lines and crevices. Also be sure to replace your spa filter, and soak all spa items in a strong bleach solution before refilling the spa.

Don’t let colored hot tub water get you down! There’s always a solution….


Carolyn MosbyHot Tub Works