Things You Should Know Before Getting In A Hot Tub
Recently while on vacation I was presented with the opportunity to go "hot tubbing" which elicited a less than enthusiastic response from myself. Once you know about water chemistry and how disgusting (and potentially dangerous) poorly treated hot tubs are it really steals the enjoyment away from the experience. So much so that I no longer go into hot tubs that I do not maintain myself. Long gone are the days of jumping into the hot tub at a major hotel chain. You simply can not un-know what you already know...you know?
This latest experience prompted me to write an article about using other peoples (or commercial) hot tubs. In order for you to appreciate what goes through my mind when presented with an unknown hot tub, this is the criteria that I consider to be the absolute minimum that I need to know before I would even remotely consider going in a hot tub. This list is not presented in any particular order in that I consider all of these items to be equally important and any one wrong answer means I will not go in the water.
How Old Is The Water?
Commercial hot tubs have fairly strict requirements for draining and filling based on the turnover rate in the spa as well as the commercial classification it is installed in. Residential hot tubs are not covered by any such laws and at best there are CDC recommendations to drain and refill your hot tub every three months. Before I would ever consider going into a hot tub I would need to know how old the water is. If the water is of unknown age, or basically anything other than brand new, I would pass on going in.
The problem with using the age of the water as a determining factor as to when to drain and refill is that the age has nothing to do with the state of the water. What if the water was just changed 48 hours ago...but for the last 48 hours the tub has been filled with filthy barnyard animals...would you go in that tub? Why not? The water is only 48 hours old...
In the real world most people are not washing livestock in their hot tubs. A very real concern however is how well the chemistry is being balanced, and how many people are using the tub. Has the tub experienced any problems with water quality since the water was changed? Was the water green for a bit but now is good after you added a metric ton of chemicals to fix the problem? When I use a hot tub I want to know how old the water is however this is really only a leading question so that I can ask more invasive questions about the sustained quality and chemical maintenance of the water. Even if I watch the hot tub being filled myself right before my eyes this still would not be enough to satisfy me...mostly because the really gross bacteria is not suspended in the water - it is stuck inside the plumbing lines.
Do You Pipe Flush Before Draining Your Old Water?
I ask this simple question to every single person I know with a hot tub. On average I would estimate that 10% of hot tub owners do pipe flushing (or even know what it is). That means approximately 90% of the hot tubs out there are absolutely disgusting and nobody should go in them. If you drain and fill your hot tub without pipe flushing then all you are doing is replacing the water but the source of the major concern remains stuck to the inside of the plumbing lines.
Biofilm is a grey and sticky substance which provides a layer of mechanical protection for bacteria stuck to the inside of your plumbing lines. Chlorine (or bromine) can not eat through the physical layer of biofilm to get to deeply ingrained bacteria. Further the biofilm acts as a food source for the bacteria helping it to reproduce. In order to strip all of this biofilm out of your plumbing system you will need to use a pipe flush (hot tub flush) product that is designed to cut through the grease of the biofilm and strip it out from inside the pipes. If you do not pipe flush your tub then the biofilm will continue to grow and accumulate inside the lines and this will lead to difficulty maintaining sanitizer levels in the water.
The biggest reason that pipe flushing your spa is so important is that if you do not the biofilm will continue to build up and encourage bacteria growth within the water. When you get in the tub and sit in front of the jets you will end up having tiny pieces of biofilm (and bacteria) strip off from the movement of the water. So now you are sitting in hot water, and the pores on your skin are open, and persistent bacteria and biofilm and being fired directly into your back while sitting in front of the jets. This is a "perfect storm" situation that can easily result in a bacterial infection for anyone who uses your tub. If you do not pipe flush your tub every time that you drain and refill the water then I would not even consider going in your hot tub and I would do my best to convince you (or anyone else) not to either. If this is all new information for you then consider reading this short article on important hot tub care tips.
How Often Do You Clean Your Filter?
My next important question before I would even consider getting into a hot tub is to inquire about how often the filter gets cleaned (and how you go about cleaning it). If you look towards swimming pool systems, or concrete hot tub filtration systems, you will realize how undersized pre-fabricated hot tub filters are. A hot tub filter is typically very small, only 50 square feet of surface are of filter medium. This is quite small and in order for a hot tub filter like this to be effective it needs to be cleaned constantly.
If you use your tub on any kind of regular basis then you should be cleaning the filter every two weeks. If you hardly use your tub at all then you should be cleaning your filter no less than every 30 days.
Hot tub filters are made from paper. Honestly they are the smallest possible filter that can potentially keep the water clear. This is one of the ways that hot tub owners typically struggle to keep the water in their spa looking good. If you struggle to know what to do with your chemistry you will possibly have a trouble with water quality or clarity. If you do not maintain your filters properly, or clean them often enough, you can count on having problems with holding sanitizer levels, turbidity in the water, and most especially - foam.
Every time you get in your hot tub you sweat. Even dignified ladies who do not sweat will glow like a pig when they get into 104 degree water. Also makeup, sun tan lotions, moisturizers, shampoo, conditioners and other impurities all contribute to the human soup which is a hot tub. What do you think happens to all of that grease and oil? It gets absorbed by the paper that your (barely adequate) filter is made from. Once the filter paper is saturated a few different things happen:
1) The pump must work harder to draw water through the filter system since the oils are plugging the paper.
2) No more oil will be removed from the water by the filter which results in cloudy water, increased sanitizer use and bubbles (foam).
3) The filter paper, under increased suction and reduced flow, will deteriorate at an advanced rate.
IMPORTANT NOTE ON FILTER CLEANING - There are two ways in which you potentially clean a paper filter and unfortunately there is a lot of damaged filters out there from improper cleaning methods. A paper filter in a hot tub can be plugged with grease and oil, but sometimes they can also get covered with scale from operating the spa water in a scaling state (saturation index). If the paper is saturated with oil then you need a degreaser cleaner. If the paper is scaled then you will need to soak it in an acid bath. If your filter is scaled and oily the order in which you correct these problems is very important. The important part of this advice is that if you expose a paper filter saturated with oil to acid you will effectively bake in the grease and oil into the paper. This is permanent and will result in you needing to replace the filter...supposing you happen to notice. Most hot tub owners will not. They will only notice the symptom of having persistent foam in the hot tub. No matter how many times you change the water or clean the filter again you always end up with foam again within a short period of time.
Scaled hot tub filters - If you are wondering if you have scale plugging your hot tub filter the answer should be easy to find. Do you have scale physically floating around in your hot tub? Do you have hard scale developing on the surfaces of your tub? Does the filter physically look scaled? If so then you might need to soak your filter in an acid bath of 7 to 10 parts water to one part of muriatic acid. This is actually a fairly uncommon situation when compared to the much more common situation of having a filter that is saturated with oil.
Oil saturated hot tub filters - When you need to "clean your hot tub filters" then 95% of the time oil is your problem...not scale. Soaking paper filters in a degreaser soap, one that is specifically phosphate free, will help to strip the oils from the paper. If however you give your filter an acid bath first then you will cook the oils into the paper and ruin the filter permanently. Many people prefer to buy "hot tub filter cleaner" but I prefer a two step approach to filter cleaning using base ingredients. For removing oils from paper filters I use automatic dishwasher detergent granules (phosphate free) to the ratio of one cup of granules to five gallons of hot water.
More times than not when you need to clean your filter it is the degreasing process that you should follow. If you discover that the filters are also scaled then you can proceed to a descaling solution however this is relatively rare in comparison to filters which are simply plugged with oils. Oily filters are the number one cause for hot tub foam so if that is a problem in your spa then the solution almost certainly relates to cleaning your paper filters better or more often.
Sanitizer & pH Levels
One of the main reasons that I will not get into a hot tub where the maintenance history is in question is due to sanitizer and pH levels of the water. Most spa owners know that you need some sanitizer in the water to stop bad stuff from growing. This is correct although the relationship between sanitizers, pH and bacteria growth is a dynamic and complicated one.
Before I get into a hot tub I need to know what type of sanitizer is being used in the water as well as what the current sanitizer and pH levels are. There are a few reasons why these values are important in determining how "safe" the water is.
Chlorine Or Bromine - While most hot tubs tend to be sanitized with bromine there are still many tub owners who prefer chlorine. Either of these sanitizers can be effective at killing bacteria and making the water safe but at the same time both potentially can be compromised in their ability to do their intended job in the water. If you were to tell me that you choose not to use chlorine or bromine in your water but instead choose a more "natural" way to keep your water safe...my reaction would be to immediately cover my mouth with the shirt I was wearing and run away from the area your spa is located. If you are confused as to why I would literally do this then you should read this informative article about chlorine free pools & spas.
Limitations Of Chlorine In Hot Tubs - While chlorine can be used to keep hot tub water safe, the main reason that it is a distant second to bromine for popularity is that chlorine struggles to be effective at higher pH levels. At a pH above 8.2 chlorine will be over 90% inactive in the water. This means the normal minimum threshold for free chlorine of 1 part per million effectively needs to be ten times this amount for the same level and timeframe for safety. The solution to this problem is not to add more chlorine, though to a certain degree this may be a good idea, but instead to make sure that the pH does not climb to and in excess of 8.2. This can be challenging since almost every aspect of hot tub operation will tend to cause the pH in the water to go up. If you have a chlorine spa then keeping your pH at 7.4 will be very important.
Limitations Of Bromine In Hot Tubs - Bromine is by far the more popular choice for hot tub water chemical sanitizer despite it costing much more than chlorine. Bromine is more effective at higher pH levels than chlorine making it more well suited to the type of environment hot tubs operate in. Bromine, just like chlorine, has an "ideal" pH level much lower than what you would want to run your spa at. Chlorine however has an ideal range much lower than that of bromine and this makes bromine more user friendly and forgiving to out of balance pH levels than chlorine. The main concern with bromine, at least for myself when I am thinking about going in the water, is that bromine requires regular oxidizer dosing in order to function correctly. Many bromine users understand that adding oxidizer will reactivate spent bromine salts and increase the bromine level...but many do not know that regular oxidizing is required in order to allow the bromine to kill bacteria. Under lab conditions it is possible to culture bacteria in brominated water where there is an established bromine residual but the bromine has not received oxidizer dosing for an extended period of time. I am not a microbiologist but the one that explained this phenomena to me summarized by saying that these unique bacteria that are able to grow under these conditions are some of the scariest things he has seen in the lab.
Hot Tub Water pH - In addition to being a concern for how well (or not well) your chemical sanitizer is able to work in your water, the pH of your water is actually the #1 cause for getting a rash from using your spa. Sure bacterial infections are possible from hot tubs, especially poorly maintained ones, but being sensitive to pH changes is far more common. The pH scale is logarithmic which means a pH of 6.0 is ten times more acidic than a pH of 7.0. If your pH is off by even a single whole number then your water could easily be ten times more basic, or more acidic, than it should be. Some people are resistant to pH changes and could bathe in black coffee without any skin irritation. Other people, myself included, are not as lucky. I have the type of skin that burns under florescent lighting and incorrect pH levels will almost certainly leave me with excessively dry or itchy skin. Before I would ever go into a hot tub I would need to know that the pH is right in the 7.3 to 7.5 range...along with everything else listed on this page.
When I am at a party where people want to jump into the hot tub these are the thoughts that are floating through my head. Everyone else is just thinking about the fun but all I can think about is a bathtub full of people all soaking in each others juices. When you ask me to go into a hot tub that I do not maintain I usually end up with a 1000 yard stare on my face as I think about the complex interaction between sanitizers, pH, bacteria, oils and just how much ass hair is currently stuck into the pleats on your filter. From many years of pool and spa contracting I have learned that there are three kinds of spa users. Those who never use hot tubs and see no value in owning such a thing, those who use a hot tub but do not share it with friends, and those who like to party. I like to think that I like to party...but when it comes to questionable hot tub water then you can count me out.
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