• It is perfectly acceptable to run your system 24/7 (and you should with a small aquarium pump). The Minimalist Filtration System is powerful enough that you can also choose to schedule a daily shutdown period of 6+ hours, where both the freezer and pump are powered off. It is important that the pump run whenever the freezer is cooling to prevent ice buildup on the walls, which reduces cooling efficiency and can damage your interior coating. I personally shut everything down for 9 hours each day.
  
  
• Run a power strip off of a wifi smart outlet (Amazon). Plug your freezer and pump into this. Also plug a second smart outlet into the power strip for your ozone. This lets you schedule a daily shut down of all devices. Plus, you can schedule and manually time ozone runs while the system is on.
  
  
• Here is a system diagram of my recommended connections: https://apex86.net/blogs/cold-plunge-blog/cold-plunge-connection-diagram

• The #1 thing you can do is shower before you plunge, with soap, all over. The microbes that ride in on your body are the main source of contamination. Even if you want to go straight from the sauna into the plunge (I love this), shower before your sauna, and towel off very well before the plunge.
  
  
• Run your ozone generator for 15 - 30 min immediately after you plunge, to kill anything you brought in. Also, run the ozone for 30 min per day on a schedule (wifi outlets make this easy), regardless of whether you plunge.
  
  
• Keep a low concentration of hydrogen peroxide (50 - 100 PPM). Use food grade 35%: https://bulkperoxide.com/35-food-grade-hydrogen-peroxide-1-gallon/ and check the concentration with test strips: https://amzn.to/3Hs2IcC (you can cut these test strips in half lengthwise and double them) If your concentration is falling quickly, you have contamination. Check the level often and keep adding peroxide to maintain it. Once you kill the microbes, the level will become very stable and you won't need to add for weeks at a time.
  
  
• Use a soft brush to brush down your plunge walls and floor every 1 - 2 weeks (get inside the corners). This prevents microbes from getting established under a biofilm that can protect them from ozone.
  
  
• Your filter should be rinsed and disinfected every 2 weeks: (https://youtu.be/vvk5EfhG18E?t=443) The included 5 micron filters can be sprayed off with your sink sprayer to remove debris. Soak the filter in the open canister, with a solution of ~3 oz of bleach, and topped off with water; for 1-2 hours. Then discard the water and rinse the filter. When in doubt, just grab a new filter; they are only a few bucks, and are a choice spot for microbes to colonize. These are my recommended filters: 
  
   https://amzn.to/3uj5UEv (6-pack)
  (make sure they are 5-micron. Sometimes they change the listing)

• With a venturi in your system, constantly injecting air bubbles, any residues from soap / detergent / personal products can accumulate in your water and lead to foaming. Make sure that you clean these things off of your body before plunging and that any clothes you wear are rinsed totally clean of detergent. If you want to keep the same water for many months, anything you add (even in tiny quantities) will accumulate. If the bubbles clear within a couple minutes of shutting down your pump, there isn't much to worry about.
  
  
• A sudden appearance of bubbles can also be a sign of microbial growth. Check your peroxide level and add aggressively if it has dropped.

In our opinion, absolutely not! Despite what you might have heard (likely from someone trying to sell you salt), adding salt to your water is all drawbacks with no benefits:

• Many people want to add salt for the benefits of transdermal magnesium absorption. But due to the short duration and extreme cold temps of a cold plunge, this will not be achieved. Your skin pores slam shut at these temperatures and your body even cuts circulation to your extremities. So, if you want transdermal magnesium, take a nice hot bath!
  
  
• Others believe that adding salt to their plunge will help keep their water clean. This couldn't be further from the truth. The ocean is a great example. Each gallon of seawater contains about 0.23 pounds of salt. So, in a typical plunge, you would have to dissolve 18 pounds of salt to match the salinity. This would be very difficult with the reduced solubility of salt in such cold temps.
  
  Even if you were able to achieve such high salinity, it most definitely wouldn't stop microbes from growing. One liter of seawater is estimated to have ~ 1 billion microbes in it. That would be about 300 billion microbes in your plunge tank!
  
  
• The drawbacks of adding salt to your plunge are that your water will now tend to rapidly corrode any metal in or around your plunge. This includes your pump, plumbing fittings, chiller, etc. It will also increase your buoyancy in the water, making it harder to stay submerged. Finally, it will leave you feeling salty afterwards, forcing you to rinse off after plunging.
  
  So, if you want clean water, skip the salt and grab our top of the line filtration system: APEX86 Filtration System

There is definitely some debate on this topic, and no definitive answer. I'll write out my opinions on this, and stick with me to the end for one that might surprise you!

Yes, a consistent plunging routine has been shown to strengthen the immune system over time. This is by way of putting stress on it, like weight training does to muscles. If a muscle was already injured, doing weight training (adding extra stress) would not make it stronger, it would prolong the recovery. Similarly, cold plunging when your immune system is already fighting an infection just adds unnecessary stress.

Also, your body's first line of defense in fighting an infection is to elevate your core temp (a fever). This is because many viruses replicate more slowly as temperature rises, giving your immune system an edge. Counteracting this response and dropping your core temp will only give the virus an advantage.

But, I think there is a valid use of the cold plunge in the very early stages of an infection. When you first feel those symptoms coming on, it becomes a race between your immune system and the viral replication. Spikes in cortisol and adrenaline have actually been shown to upregulate your immune system, as discussed by Dr. Huberman: Boost Your Energy & Immune System with Cortisol & Adrenaline | Huberman Lab Essentials

So, in my opinion, doing very brief plunges can harness this phenomenon to our advantage. Keeping the duration very short is the key, because we are just after the initial shock and hormone response, not the drop in core temp. I will jump in and immediately dunk my head, staying in for 30 seconds or less. Then, prioritize warming back up using your environment, warm drinks, and extra layers of clothing.

My personal protocol here, when I feel the first signs of illness:

1. Prioritize high quality sleep, with a bit more duration compared to normal.
2. Upon first waking, when your core temp is naturally near its low point, I hop in the sauna. I don't push the duration too long. You aren't trying to sweat your way into dehydration.
3. Hop in the plunge for a 30 second blast with head dunk.
4. If time allows, hop back in the sauna for a few minutes to make sure my core temp stays up.
5. Wear socks and some extra clothes to help keep the core temp up.
6. Stay hydrated!