Why Did My Hot Tub Filter Turn Blue?(Solved)

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Why Did My Hot Tub Filter Turn Blue?

Your hot tub filter turns blue because of its exposure to too much chlorine. It happens to filters when you over-chlorinate the water. The chlorine reacts with the bromine in the filter, turning it blue after a while. If you use bleach as a sanitizer instead of chlorine, it may also happen.

Bleach has no bromine and is a weaker sanitizer than chlorine. Chlorine will bleach a filter over time.

You can restore your hot tub filter to white by adding a brominating product, like Bromo-Flo . Or you can replace the damaged filter with one without any bromine.

If you use a bleach sanitizer in your tub, consider switching to an all-chlorine system with lots of daily shocks.

Cooking in the hot tub or drinking in it can cause staining of your filter. A stained filter won’t hurt anything. But if you leave food or beverage residue on the filter, the bacteria growing on it can stink.

Over-use of bromine can also turn your tub grey and dull-looking. That’s not just ugly; it indicates that nutrients are building up, encouraging algae growth.

Hot Tub Filter Has No Suction

Hot tub filter – it’s a utensil that you can use to filter the water in your hot tub. It sits on the bottom of your hot tub, collects any debris, and traps it for easy disposal.

There are two types of hot tub filters: Cartridge and sand filter. Cartridge filters use a thin, porous material, with the water passing through it and trapping any dirt or debris.

This filter is typically more convenient to clean and maintain but less effective than a sand filter.

Sand filters are at the bottom of your tub and work by trapping particles as they pass through them.

Your hot tub filter has no suction because it’s clogged with mineral buildup. These are the best ways to clean a hot tub filter.

Anywhere you have water, you need a filter. So if your hot tub isn’t working correctly and your filter is dirty, you may have some work.

You should know that vents in your Spa might get clogged up with dirt. Learning how to keep the plume of water flowing like it’s supposed to can help take care of both problems quickly and easily.

While you can use a cheap shower head and clean the filter, you should know that the average person cannot unscrew an actual shower head from their wall.

It’s usually screwed in there, and it’s pretty hard to get down to the actual filter. Even if you could take it off, most people cannot clean the filter themselves, with bacteria spread outside their tub.

You’ll also find that not everyone has the same type of filter in their Spa. Some filters are like a filter you would put in your fish tank.

For example, the cascade filter(Amazon Link) allows water to flow through it, but if you clean out the inside by taking off the outside shell, there is no way to get all the gunk out from between the filter’s pleats.

If you need to clean this filter, you can use special chemicals or even a baking soda and vinegar mixture.

This will help remove the hard water mineral buildup and make the filter new again. You have to ensure that you put in enough of the cleaning solution to soak it.

If you don’t soak it long enough, the hard water mineral stains could remain in place and will clog up the pump again after the tub has been running for a while.

How Do I Know If My Hot Tub Filter Is Bad?

You can know if your hot tub filter is bad by simply looking at it. If the filter is dusty, cracked, or has chunks of hair sticking to it, your filter may be bad.

If the water in your tub does not look clear and inviting and smells slightly like chlorine all the time (or smells like another chemical), this could also mean that your filter is bad.

If your water is cloudy and you can’t see the bottom of the tub, this could be a sign that your hot tub filter needs replacement.

The best way to check and maintain your filter is to run it with a water test kit. Here are some examples of these kits:

Aquadestin Hot Tub Water Filter Test Strips – $10.97 on Amazon – This would be good to check how clean you are getting on average and check for future changes in water quality.

The First Alert WT2 Water(Amazon Link) Quality Tester – $24.88 on Amazon – This would be good for checking the quality of your hot tub water regularly and to help determine if you need to replace your filter more often.

The Pool Supply Superstore Water Quality Tester – $6 on Amazon – This is a small, inexpensive water test kit that can give you enough information about your hot tub water, including chlorine and PH levels.

Fibreglass hot tub filters and cartridge filters work the same way. The filter’s inside will be a maze-like array of pleats where the water passes through to get filtered.

Each pleat gets connected by a hose that connects to the next pleat. Inside each hose is an inner liner, a foam strip, and an outer rubber strip.

The outside of this structure has a pleated filter material that traps all pollutants in the water. If the filter needs removal, you will want to replace these liners and foam strips.

How Do You Unblock A Hot Tub Filter?

You can unblock a hot tub filter by heating water in a pot and then pouring it through the filter. This will break down the clog, which should flow through much easier.

Another option is to get a new unclogged hot tub filter.

Hot tub filters are notorious for getting plugged up with calcium deposits which can cause water problems if not removed correctly.

You can remove this blockage in several ways, including running the filter under cold water or boiling a pot of water and pouring it through to loosen things up before plugging back in again.

You should clean out filters regularly to avoid this problem. 

Remember, you should change your hot tub filters at least once a year to maintain a good full-body massage and avoid this problem.

Why Does My Hot Tub Have Two Filters?

Your hot tub has two filters because one filter is not enough to keep your hot tub water clean.

Your hot tub has two filters because it’s nearly impossible to have one filter catch all the particles that can make their way into your hot tub water.

Why Did My Hot Tub Filter Turn Blue?

One type of particle will cling to one filter and get caught in the other, while another particle will go through both filters unharmed.

When one filter gets clogged with particles, the other filter is still clean and able to catch more particles.

If you have ever watched your hot tub’s filter system or have used a “live” test kit, you know that one filter will clog up quickly.

The other filter will continue to stay relatively unclogged for some time, hopefully, a long time.

The more often you use your hot tub, the faster one filter will get clogged. The more people that use your hot tub at one time, the quicker both filters will get clogged.

The harder you try to clean your water, the faster both filters will get clogged. The more you have suspended particles in your hot tub’s water (high TDS), the quicker both filters will get clogged.

The “clean water” that comes in via your hot tub’s filter system is not clean enough to meet most people’s needs. It will irritate skin and eyes. It also has impurities that are not good for you.

If you must have clean hot tub water, there is only one way to do it: Spa owners and water treatment professionals will tell you: Buy a filter system like PUR or Bio-Pur or SpaRite or the like.

The cost is high, but the benefits are great. You will have clean water and no more effort on your part.

Those who can’t afford to spend hundreds of dollars on water treatment can spend a modest amount of time and money maintaining their hot tub filter system.

The first step is learning how to get whatever particles you already have in your hot tub water out of the water.

If you want your hot tub water to be clean, you should try to remove most or all particles. Your filter system will not remove everything, so you must supplement it with a method of removing particles.

Why Does My Hot Tub Say Filtering Suspended?

Your hot tub says “filtering suspended” because you filled the tank with too much water, and it needs to cycle through again.

The water in the hot tub tank gets constantly filtered between cycles.

When you add too much water, the filter cycles will take longer to complete, eventually locking up and suspending filtering until you lower the amount of water and allow it to catch up.

The filter cycles happen every 30 minutes or with each hot tub use. Cycling through takes a certain amount of water, depending on the hot tub model and size.

You should only add water to a hot tub when temperatures are below 25 degrees Celsius to avoid thermal shock unless you have a thermal cover.

If your hot tub says filtering gets suspended during this time, you mustn’t use the jets or turn the heat up as this could damage the pump.

Can You Clean Hot Tub Filters With Bleach?

Yes. You can clean hot tub filters with bleach. Here is how to do it:

First, turn your hot tub off and disconnect it from the power source. Next, prepare a solution of water and bleach – 3/4 cup bleach to 1 gallon of warm water.

Remember to wear gloves, goggles, and other protective gear. Carefully pour the mixture over the dirty filter or filters until submerged.

Wait between 30 minutes to 60 minutes before removing the filters from the bathtub so that they can soak long enough for a good disinfectant bath.

Rinse the filters in a tub of clean water and add a new bleach solution to the hot tub as necessary.

Do not use this method on a damaged filter – it can be challenging to get back into shape after you have retrieved it from your hot tub.

Also, never use baking soda or other abrasives to clean a filter.

Can You Put A Hot Tub Filter In The Dishwasher?

No. You cannot put a hot tub filter in the dishwasher. A large hot tub filter has a complicated design, so it will likely not be the same afterward if you could fit it in your dishwasher.

If you have a dishwasher with filters like this, it may still work — check. But if your dishwasher doesn’t have filters or you need to clean the filter by hand, here are some tips on removing them.

If the filter is full of water, it will take a long time to dry thoroughly, and you may need many towels under running water.

If it’s still full of soap, it will get stuck in your dishwasher and not work as expected.

To remove the filter from the hot tub, turn off the water line and drain it. The filter should come out quickly after that.

Avoid removing the filter unless you have to; it’s better for the filter to circulate water than to sit in a bucket.

If the filter is not full of water, take it out and remove it from your dishwasher.

Please put it on a towel under your hot tub’s waterfall or on its top to dry the filter. The hot water will help the towels absorb more water quickly.

Run clean water over it and use multiple towels if needed until all the insides of the filter are dry.

If your filter is dirty or has a lot of soap, you can remove it with soap and water. Use a cloth to scrub the dirty parts with soap and water.

After that, please remove any remaining soap by spraying the filter with clean water while scrubbing it again. If the filter is still dirty, use mild dishwashing liquid to clean it again.

If your hot tub filter is not clean enough to scrub out thoroughly, you can spray the inside of the filter with soapy water.

Please turn off your hot tub, drain it, and then unplug it from both electric outlets.

Then soak the filter in a large container of soapy water overnight or until the soap comes off easily in your hands.

If you have a dishwasher, put the filter in it with soapy water and follow your dishwasher’s user guide.

After that, rinse the filter thoroughly with clean water before putting it back into your hot tub.

If you have cleaned your hot tub filter and it doesn’t need replacement, you can put it back into your hot tub.

If it’s full of soap, drop some fresh water in to fill it, then run a cycle with distilled water to rinse any soap left behind.

You can also use a hot tap water filter in your dishwasher and fill it with warm tap water to soak overnight.

If the filter is full of food debris or soap, you can throw it in the trash.

Also, if your hot tub needs cleaning and you do not have a dishwasher, it’s not necessary to ask permission.

Gently scrub the outside of your hot tub with a brush and lots of hot soapy water using a long-handled scrubbing tool or chemicals.

Unplug it from both electric outlets before cleaning if you have a dishwasher. Remove the filter from your dishwasher and put it back in the hot tub after it’s clean and dried.

Why Is My Pool Filter Bluish-Green?

Your pool filter is bluish-green because you have algae growing on it. You should vacuum the filter bag or clean the filter with your garden hose.

You may be low on chlorine, in which case you should add liquid bleach to your pool and make sure to shock it frequently.

If this continues, it’s time for a new filter bag and possibly a new cartridge. It may also be time to adjust your pool’s pH;

If you don’t know what that means, please speak to someone in charge of pools at a store near you.

If your pool has an electric pump and you don’t want the filter to be on all the time, try the following.

Put a “dipstick” with a long hose in the pool water until you can see that it’s clear. This will allow you to put soapy water (or regular water) into your filter anytime.

If this doesn’t help, ensure you cover the filter with a floating barrier and do not sit in a plastic bag.

If the filter is getting harder to clean and you can’t seem to get it to stay cleaner for long periods, then you should service the filter.

You can get a professional to perform this service or do it yourself if you have instructions.

Carefully follow the instructions that came with your water treatment system, but first, make sure that sufficient water is available in your pool to allow this process.

Inspect all hoses and connections before use. It’s easy to forget about this step, but it’s necessary for your safety and the safety of the hose.

Inspect all hoses (including electrical connectors) for leaks, cracks, swelling, and fraying. It is also essential that you be familiar with how to shut off your pump safely if you need to do so.

Avoid shock treatment if possible because it can be dangerous when done incorrectly. Be sure to follow the instructions closely so you don’t make a mistake.


Hot tub filter cleaning is an essential part of maintaining your hot tub. Make sure you clean the filter every month, and if you notice water with a blue tint, clean the filter immediately.

This will help prevent hard water from building up on the outside of your hot tub.


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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