Should You Shock A Hot Tub After Refilling?

Should You Shock A Hot Tub After Refilling?

Should You Shock A Hot Tub After Refilling?

Hot tubs are large pools filled with water heated to anywhere between 104 degrees Fahrenheit and 104.6 degrees , which is warm enough to make you feel clean but cool enough that it won’t burn your skin.

The hot water replaces the air in the tub, so you’re sitting in an enclosed space of heated fluid where you can relax and enjoy yourself.

A hot tub is an excellent investment if you don’t already have one. It’s an exceptional way to enjoy some time out on a fantastic evening, and it has some efficient uses too.

A hot tub can help your body and mind relax, and it can also relieve back pain, promote sleep and reduce stress.

Should You Shock A Hot Tub After Refilling?

No. Shock treatments can harm plumbing and fixtures, and the water in your hot tub is already clean. You can turn on the jets or leave it unplugged for a few hours to circle the water and let it cool before turning it back on.

I recommend draining the water, scrubbing it down with a brush or pressure washer, and refilling it to clean a hot tub.

This will help prevent any buildup and keep the water cleaner for longer.

When Should I Add Chemicals To My Hot Tub After Refilling?

You should add chemicals as soon as possible after a full refill of a hot tub. Waiting this long can damage your hot tub, as well as other parts of your home.

You should add chemicals in one of three ways. To add chemicals with a chemical dispensing bottle, set up a chemical station by placing the chemicals within reach of a pump and electric valve.

With this option, you can add the chemicals during the refilling process.

The other two options require that you dispense the chemicals from an automatic hot tub dispenser (chemical injector). I will go over these options below.

For the first option, using a chemical dispensing bottle, fill the bottle with chemicals, place the stopper in the bottle’s opening, and screw the cap on tightly.

Place your fingers through straps and adjust to fit snugly for maximum control.

The second option is an automatic hot tub dispenser that automatically adds chemicals at different levels during refilling.

You can achieve this by setting up an automatic chemical feeder at a certain water level in your hot tub.

The third option and my recommended method for removing chemicals are chemical feeders. Chemical feeders get installed at the bottom of your hot tub.

Some hot tubs have automatic chemical feeders that refill when the water level rises.

Chemical Feeder

Chemical feeders have a generous amount of space for installing chemicals, holding 100 gallons or more. The feeder must completely refill before you can add chemicals.

Chemicals are automatically dispensed into the hot tub as needed, and they boast keeping inside the chemical feeder.

You can easily adjust the number of chemicals dispensed into your hot tub.

A chemical feeder also eliminates spills and potential damage to your chemical pump. It ensures chemicals are always available at the proper concentration.

It’s crucial to maintain the water balance in your hot tub(Amazon Link) by replacing and adding chemicals as needed.

After a full refill, you can use an automatic chemical feeder to ensure your hot tub gets what it needs every time it needs it.

This is an excellent option for anyone who uses their hot tub infrequently or who wants to make sure their hot tub is maintained correctly when they are using it.

Do You Shock New Hot Tub Water?

Yes. You will probably find your hot tub cold and slimy during the first few hours. This is because new hot tub water contains chlorine gas which will react with any organic matter in the water (such as urine).

The chlorine gas will kill any bacteria but will also smell awful. The shock treatment kills the bacteria and eliminates the smell.

Besides killing organic matter, the chlorine in your hot tub water will sanitize the water. Chlorine is a pretty strong sanitizer, so use these chemicals if you’re spending time in your hot tub.

Soak in a chemical bath for about 15 minutes to kill bacteria and sanitize your water for the first few hours.

The most important thing to do after bathing is to change the hot tub water. Don’t just drain it and refill your tub with fresh water.

This causes a buildup of swimmers’ body oils, making their skin slippery.

Note: Do not use hot tub chemicals such as chlorine or bromine products in your hot tub during this time.

Can You Add Shock And Chlorine At The Same Time To A Hot Tub?

No. shock and chlorine are incompatible. Never, ever add both at the same time unless you want to get a chemical burn and a chlorine gas leak.

If you have chlorine in the water simultaneously, it will cause pitting or corrosion of the metal parts and rubber components of your spa and can even attack your shell if left long enough.

This is because of excess chlorine produced due to mistiming when adding these materials and will not come out over time, as they are incompatible.

The best-case scenario is that you’re going to have a lot of expensive repairs. The worst-case scenario is that you’ll poison your water and end up in the hospital.

Here’s what to do if you’re in this unfortunate situation:

  • Unplug your hot tub immediately.
  • Flush it with fresh water for ten minutes continuously and let it sit for 20 minutes before returning it to service.
  • Do not use the hot tub until fully re-chlorinated.
  • Dispose of the shocking water in a waste container with a lid.
  • If you must use it again, never add chlorine to the shocking water and flush before using it.
  • Make sure your hot tub has enough shock in it before using it again.

Is Liquid Chlorine Better Than Shock?

Yes. That’s right; chlorine is a better option for your swimming pool.

Liquid chlorine is more expensive than dry chlorine, and you have to replenish it more often. But liquid chlorine lasts for three weeks versus just five days with dry.

You have to add liquid and dry chorine in 3/4 gallon increments, but liquid and solid shock have different effects on the pH levels of water.

Shock decreases the pH to 7.4 – 8. The water with dry chlorine goes to 8.2, and the water with liquid chlorine goes to 7.7 – 8.2.

The lower the pH, the more frequently you have to adjust it to avoid the green hardening of pools, a serious problem leading to tile failure, cracks in plaster and concrete walls, and overall pool damage.

Shock also dissipates into the water.

In contrast, mild liquid chlorine goes to a pH of 7.4 after one week and 7.8 after two weeks and remains stable between 7.8 to 8 over the entire three-week period.

One key point is that the pH level should not drop below seven before adding shock, which causes scaling in plaster and concrete.

With potentially serious damage to your pool and its liner (if installed on a concrete slab).

There are two different types of shock:

  • Liquid chlorine is better than dry chlorine.
  • The three-week liquid chlorine is better than the five-day dry chlorine.

The benefits of shock are:

  1. They cause rapid and dramatic pH changes in the water, such as keeping it at 7.4 or below, which avoids green hardening of pool plaster and concrete, the problem with scale, algae blooms, and algae scum on a pool surface.
  2. They effectively eliminate cyanobacteria, which causes cyanotoxins (i.e., cyanotoxin).
  3. They cause rapid and dramatic pH changes in the water, such as keeping it at 7.4 or below, which avoids green hardening of pool plaster and concrete, the problem with scale, algae blooms, and algae scum on a pool surface.

The importance is that the pH level should not drop below seven before adding shock, which causes scaling in plaster and concrete, with potentially serious damage to your pool and its liner (if installed on a concrete slab).

Possible adverse effects of shock include:

  1. The chlorine concentrations from the shock might be too high for human contact.
  2. Because it is too strong, it will evaporate quickly.
  3. The shock might contain other contaminants, such as heavy metals, that might be harmful.

But, no matter the adverse effects of chlorine, it is still better than any alternative.

Is Shocking A Pool The Same As Adding Chlorine?

No. Adding chlorine to your pool is a chemical process; while shocking, it is more of a physical process.

Shocking the pool means adding oxidizer tablets to the water, which creates an oxidative reaction that eliminates chloramines and bacteria.

Adding chlorine to your collection dilutes the chemicals over time and can cause cloudy or odiferous water if you don’t know what you’re doing.

You can also shock your pool by dumping chlorine into the water, but you need to follow a specific process for it to work as expected.

Adding chlorine directly to the water is inefficient and dangerous because you can’t accurately measure how many chemicals you’re adding.

Shocking your pool is also called super-chlorinating or adding acid to dissolve chloramines.

You can rid your pool of algae by shocking it with a chemical called chlorine dioxide, which is more efficient than other types of chlorine.

Chlorine dioxide is available in tablets and powder, and you dissolve the tablets into water or mix the powder into water.

You can also purchase bleach-based shock products that have been specially formulated to dissolve chloramines.

When you’re shocking your pool, you should always shock it at night with no swimmers around.

The pool should be at least 10% full when you’re shocking it, and it’s best to shock the pool about ten days before you plan to swim in the water again.

You can also remove chloramines by shocking the pool with a sanitizing agent such as bromine or solid chlorine dioxide.

These shock treatments eliminate chloramines by reacting and turning them into harmless compounds such as ammonia or nitrogen.

Shocking your pool isn’t recommended if you’re trying to lower the amount of chlorine in the water.

You should add less chlorine to the water until it’s at a comfortable level. It takes time for chlorine levels to adjust when you lower them, and shocking will make it more challenging to get your levels right.

Do You Shock Pool After The Rain?

No. That is a dangerous habit. It is crucial to avoid that kind of weather altogether, even if you plan to swim after the storm passes.

The water might be clear, but at best, it will still be cold, and you could also suffer from a heart attack from an electrical shock.

Please avoid the shocking pool for your safety and others who may be around you when the storm is going on or afterward.

A shocking pool is not a good idea in any weather. That is why we recommend staying away from the water during a thunderstorm.

You may think you can stay in the pool after the storm passes, but you don’t know what might happen to your body while floating around.

During a thunderstorm, lightning can cause temporary electrical shock or death.

A shocking pool may also be dangerous to your health, even if there are no electrical discharges. The temperature of the water can drop dramatically.

This drop-in temperature could cause hypothermia, a dangerous condition in which your body temperature drops dangerously low. This can affect your heart as well.

Can You Over Shock A Hot Tub?

No. A hot tub gets built with a heating system that progressively adds heat to the water to keep it pleasing throughout the day.

The system continuously monitors the water’s temperature and adjusts heating appropriately.

If you have not used your hot tub for an extended period, it may appear as if it includes what appears to be a shock treatment option.

This is typically just a way that you can change out the old chemical water for new chemicals, which will remove any leftover residue from previous chemistries from your spa.

This item is only available on specific models of hot tubs.

If you don’t have this option available, or if your tub has been running for a while, there is no need to worry.

Your spa comes with a built-in system that will assist with keeping the water at an appropriate temperature throughout the day, so there is no need to shock the water.

Should I Fill The Hot Tub Before Electricity?

Yes. You can fill a hot tub before electricity. It would make heating the water quicker.

I suggest filling it with water but not turning on the heater until you are ready because, once it’s turned on, you will fill your hot tub with warm water.

If you want to fill your hot tub before electricity, then first turn off power for all but one circuit breaker. Next, use a hose to fill the hot tub about 1/4 full of water.

Then turn on the water for the circuit you turned the power off on. For example, if I turned off breaker number 3, I would turn on the water for circuit breaker number 3.

Do this until the hot tub is about 1/4 full or so. Then lastly, turn your hot tub heater on (if there is one).

If you have a cover for your hot tub, put it on before turning the heater on. Turn it on at its lowest setting.

If you have never worked with an electrical system before, it may be a good idea to call a licensed electrician.

Fill a hot tub with water before electricity is not something you should be doing. The electric company will fix the problem free if anything goes wrong.


Shocking the hot tub is not recommended for many reasons. It is not suitable for the long-term health of your tub; it is not safe to do, and it accomplishes nothing other than wasting time and money.

If you have a spa that you cannot adjust with a heating system, make sure that you never fill your spa with water before turning on the heater.

For example, if your water heater does not provide heat change (most don’t), then make sure that you always fill your spa with water before turning on your heater.


Hi! I' am Tom. I was a manager in one of the biggest stores for over 10 Years, am also an SEO by night. I don't like to call myself a blogger; they are very analytical, do email marketing, and know all SEO stuff. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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