What is Hot Tub Shock?

When you’re looking at water care articles or instructions for clearing up funky or smelly water, you’ll frequently see people advising to shock your hot tub. Today we’ll have a look at what exactly shocking does and how to do it to your spa water.

What exactly is a hot tub shock?

When you use a hot tub sanitizer like chlorine or bromine, these sanitizers work to kill the harmful bacteria and particles in your spa water. The spa sanitizer does its job and the bacteria is dead, but the remains of the bacteria and the sanitizers are still lingering in your hot tub water.

Spa shock is a treatment for your hot tub water that off-gasses these dead bacterias, oils, sweat and even used up sanitizer particles from your water so that they can harmlessly evaporate out of the water, leaving your spa much cleaner and water quality substantially better.

What’s the best way to shock a hot tub?

There are two common ways to shock a hot tub: using a chlorine based shock or a monopersulfate based shock.

  • Monopersulfate (non-chlorine) shock is an oxygen based shock that works by oxidizing the water to off-gas the contaminants. Monopersulfate shock works quickly to clean your water and usually only needs to off-gas for about 15-30 minutes. The result is clean, clear water in a very short period of time. Since oxidizing shock is gentle on your spa parts, it makes it a great choice to use about once a week in conjunction with your normal chemical maintenance routine.
  • Dichlor (chlorine) based shock works by super-chlorinating your water to kill and destroy those organic bacteria and contaminants in your water. If using a dichlor shock, you’ll likely notice a heavy chlorine smell and you’ll usually need to wait a few hours for the chlorine spike to gradually come back down. While it’s extremely effective at removing organic materials from the water, adding in this super high level of chlorine does make your water a lot more acidic which can permanently harm your spa jets and other internal spa components after consistent use.
  • Important tip: if using spa enzymes in your water, you’ll want to avoid monopersulfate shock as it greatly reduces any benefits introduced by the enzymes; stick to a dichlor shock with enzymes.

Sani Marc Spa Shok Ultra Oxidizing Shock Treatment

Spa Essentials Quick Clear Spa Shock

Spa Synergy Clear

A chlorine-free monopersulfate shock treatment to restore clarity and cleanliness in your hot tub water. A monopersulfate based shock to use in your weekly water care routine. Oxidizing and clarifying packets for convenient, clean and clear water.

Do I need to use hot tub shock?

Using a spa shock is essential for clean and clear water. A lot of common water issues such as foggy, cloudy, smelly and murky water can be resolved by simply shocking your water.

When should you shock your hot tub?

Hot tub shock should be a part of your regular chemical maintenance routine. With average spa use of 2 people using the spa about 2-3 times a week, you’ll want to shock your spa about once a week in conjunction with your weekly chemical maintenance (always after soaking). If you use the spa more or less than that, you’ll need to adjust your maintenance routine accordingly.

If your hot tub has been neglected for awhile or had a period of heavy use (like everyone getting in the tub during your holiday get-together), you can shock it right away to give the water an added boost to help deal with the extra load- just make sure to keep up with your regular shock and chemical maintenance routine. For more info on an ideal water care routine, have a look at our tips here.

Important tip: always remember to run your jets on high and leave your cover off for about 30 minutes after shocking your hot tub. This allows the chemicals to fully circulate throughout the water and off-gas without damaging your thermal cover.