How‍‌‍‍‌ to recognize when an outdoor hot tub filter is dirty?

As more and more outdoor leisure lifestyle ideas surface, people are installing outdoor spa hot tubs at their homes primarily for relaxing, hydrotherapy, and enhancing a backyard living experience. In addition to daily bathing, these tubs, unlike the typical bathtub setup, get dirty faster due to open-air exposure and a combination of water circulation, filtration, and water treatment systems that keep water conditions at maximum operational levels.

The filter is the backbone of the water circulation system which filters away impurities like hair, dead skin, dust, oils, and other foreign materials and keeps the water clean. Still, people are usually unaware that these problems are linked to the main issue which in most cases is a clogged filter. The filter has only a basic design and yet, since it is a continuous operation, it constantly works and when it collects too many contaminants it becomes less efficient and even entirely blocked. The failure to spot such an issue early on or even not acting on it not only will result in the degradation of water quality but will also place increased load on equipment which could result in damage of core parts of the spa hot tub system such as, circulation pump, and heater.

Therefore, how can you find out whether your outdoor whirlpool hot tub filter is clogged? How often do filters need to be cleaned? What should one do if clogging becomes apparent after the filtration process? This piece addresses these topics in detail to help spa hot tub owners form a regular maintenance habit, prolong equipment life, and achieve a comfortable and safe spa experience.

Why does the filter in an outdoor spa hot tub frequently get clogged?

These spa hot tubs mainly employ circulation and filtration system for filtering water. Once the pump is turned on, water is sucked in at the filtration area, goes through the filter, and gets returned to the tub. As water and filtration continuously take place a gradual lowering of impurities within water comes on.

Filter has three tasks of paramount importance. Firstly, it removes the visible particles such as, hair and skin cells, dust, leaf fragments and insect matter. Secondly, it removes small particles and organic matters like residues from sunscreen, beauty cream, and body oil. Lastly, it prevents the circulation pipe, jets and pump from getting blocked with lots of debris.

Pleated filter elements make up filter cartridge which in turn have the purpose of creating more filter surface in an attempt to maximize filtration efficiency while still using a compact sized filter. As the amount of contaminants on the cartridge gradually increases, so does the resistance of water passage. Eventually this causes poor filtration performance.

Standard maintenance guidelines advise that filters of residential outdoor spa hot tubs are rinsed once every 2 to 4 weeks and replaced every 3 to 12 months at varying rates depending on a house's hot tub consumption rate, water chemical levels, and number of bathers. A spa hot tub filter will become blocked quicker under such circumstances like heavy usage, if a spa hot tub is nearby to trees and if it is located in a dusty area.

Major symptoms of outdoor spa hot tub filter clogging

Filter clogging is not the kind of problem that hits all of a sudden, rather it is something that happens gradually. Many of the customers only get to the point where they realize something is wrong with the filtration system at the stage of significantly deteriorated water quality or equipment is triggering an alarm. It is not actually an easy task to pinpoint clogging at early stages with a single inspection. However, by simply taking note of the spa hot tub use on a daily level and doing some kind of comparison can enable you to catch the symptoms of clogging early!

1. A weak water flow is mostly the first sign of filter clogging

For an outdoor spa hot tub, water flow strength is definitely a reliable measurement that reflects the filtration system's condition and functioning capacity.

One of the easiest ways to check if your filter is clogged is by feeling if your massage jets' pressure has dropped significantly or if the water flow is not as strong as it normally is when you are activating the hydrotherapy jets. These two factors almost definitely indicate filter clog because the filter being blocked means water is not able to pass through the cartridge smoothly and hence, the pump can't draw more water and the overall efficiency of the circulation system can not be achieved.

Under normal conditions, a spa hot tub water should circulate regularly. If there are a lot of blocked filters, the water will be hardly passing some of the jets, the massaging effects will be very little, or there will be a weak water flow in some areas.

You should keep in mind that weak water flow is definitely one of the major signs that a filter is clogged in your outdoor whirlpool hot tub system but other parts or systems such as the pump, blocked air intake, etc might also cause the same problem.

Filter problem should be checked early and it is probably the number one source for these types of issues.

2. Water that is cloudy could be one indication of a less efficient filtering system

Many users often think that their spa hot tub water used to be quite clear yet lately it is becoming cloudy even though they continue to do the sanitizing treatments. While this problem is related to the chemical components of the water, it can also be related to that your spa hot tub filter has a problem. When a lot of impurities have accumulated on the surface of the filter, it reduces its ability to filter and as a result, particles suspended in the water are not quickly filtered out, and therefore, the clarity of the water is compromised.

Some usual signs are:

Water is cloudy or looks white or milky;

Debris floats constantly on the surface of the water;

Water takes more time to clean after use;

Still water looks dirty even after long time filtration.

In outdoor whirlpool hot tubs, water filtration and sanitization are the most important factors, working together, in determining water quality. Therefore, if filter doesn't effectively remove the organic contaminants, the usage rate of the sanitizing agents becomes higher since there are more organic pollutants and these will need to be destroyed through oxidation.

3. Louder pump circulation noise is a possible manifestation of greater resistance in filtration

A minor alteration in the noise generated by the circulation pump is the other indicator one may easily miss.

Normally, your circulation pump operates with a steady, consistent level of background noise when the system is running. If the filter becomes clogged, then the resistance of water flow significantly increases so that the pump has to work harder in order to keep the system circualting.

Symptoms can be:

The pump sound is significantly louder than in the past;

Lightly vibrating pump;

Noise level rises when you select the massage feature.

If the pump runs against a high resistance for an extended period of time the motor load increases resulting in a shorter equipment lifespan.

A study reveals an average efficiency loss of about 10–30% when low-level water flow through the system continues for a long time. The possibility of breaking down also increases at this phase of operation. Therefore, keeping your filters in clean condition regularly is extremely important not only in order to get great water appearance but also to protect your core spa hot tub machinery. 

4. Delayed heating may also be linked to the filter

This often causes suspicion that there is a problem in the heater when users observe an outdoor whirlpool hot tub heater working slower than anticipated.

A proper operation of the heat system is a prerequisite for the continuous flow of water. Only then, by passing the water through a heating element, a uniform temperature can be established in different areas of the water.

With slowed circulation caused by a partially blocked filter, heat generation from the heater cannot disperse quickly. Therefore, only a very moderate temperature increase will occur in such a scenario.

To give an example, a working spa hot tub may achieve a temperature between 6 and 12 hour periods while a system whose water flow is restricted (due to filters) will take much more time than that.

In such cases, replacing the heater out of nowhere will cause not just an increase in cost but also the core issue remains untouched. In that case, checking the filter should be an integral part of the troubleshooting process. 

What are the methods for checking a clogged outdoor hot tub filter?

There is no need to have expensive, complex equipments to figure out if your filter is blocked. As a matter of fact, users can carry out an approximative check in a short, easy way.

First and foremost, make sure to have your outdoor whirlpool hot tub system switched off before touching anything, the main reason being safety. Then, take off the filtration component and have a look at the physical state of the surface of filter media.

It might suggest that the filter has absorbed a fairly large proportion of impurities if you see quite a lot of:

oils or greazy layers;

sediments and dirt;

vegetable debris like leaves;

white mineral deposits;

residue from green algae;

Second you can try the water flow method. If water flow gets much stronger when you put the cleaned filter back, it means that the main reason for this problem was clogging.

Also, you can have a quick glance at the changing filter color. Most of the times, when you've been using the filter cartridge for a while, this will go from pristine white color to gray, then to yellow and finally to dark brown. If you are not able to figure out why this is happening, it is likely that the material inside the filter has already taken hold of a great deal of particles that are contaminants and dirt, respectively.

What makes outdoor spa hot tub filters more susceptible to getting clogged?

In most of the cases an outdoor spa hot tub filter will have to handle much more load of impurities compared to its indoor counterparts.

First of all, the outdoor environment is so much dirtier and there is so much of dust and pollen that they get stuck inside. If insects also are attracted to the water and then they get killed, you will have the insect debris as another category of pollutant on top of leaf and dust particles. A filter is a major component and so when a tub is near or has trees that can shed leaves, the load of dirt on the filter increases dramatically and so it is going to have to work at a higher capacity.

On top of that, the human body itself adds a major part of pollution for spa hot tubs. Body secretions like sweat, sebum (which we refer to as body oils), body lotions and skin care products along with sunscreen are the stuff that a user leaves behind in spa hot tub water and all are to a greater or lesser extent organic in nature. They tend to stay close to the water and are really hard to remove but at the same time, their presence will only add insult to the existing situation on the filter and water treatment system side in terms of work load and burden.

Another factor that can change how long your filter is going to last or what the quality of your hot tub water will be, is of course your tap water, which we refer to as water hardness if it is high in minerals, because then you are likely to also get limescale deposits on the surface of your filter which would reduce its efficiency of functioning.

Clogging of outdoor whirlpool hot tub filters is, therefore, quite normal, especially since they have to run on a system which is very long-term in nature and also quite high maintenance in a way.

How frequently should one clean the spa hot tub filter in the yard?

Cleaning your spa hot tub filter is going to vary depending on how you use it. So it's more of a case-by-case basis.

In case you only use the spa hot tub 2 to 3 times a week it's a good idea to clean it every 2-4 weeks.

On the other hand, it's a better bet to keep track of it on a weekly basis if you regularly use it or share it with others.

Of course, even if you don't get the spa hot tub regularly, you still might have to clean more often depending on the environment. Routine cleaning is usually just washing with clean water; just don't direct a high-pressure sprayer onto the filter cartridge because the pressure can be very damaging to the filtration material.

This deep-cleaning step should be carried out approximately every two to three months as a rule. This cleaning not only makes sure the removal of oils and minerals but also tackles more stubborn dirt that would otherwise be impossible to clean just by rinsing.

How do you clean an outdoor whirlpool hot tub filter in the best way?

Thorough cleaning leads to the filter regaining much of its filtering ability.

Step 1: Shut the unit off and locate the filter and take it out.

Step 2: Using water of average pressure, you can wash the filter. It helps to start at the highest point and work through to a lower level to let all the dirt run off following the direction of filtration.

Step 3: Soak deep in water if your filter has a layer of oil or grease stains. Then put the filter in an industrial cleaner solution for several hours if a thick layer of soil is there on the filter.

Step 4: After soaking, clean all the soap off from the filter so no trace of cleaner remains.

Step 5: Get the clean filter fixed back in place and verify that the water flow is restored to the previous flow levels before removing the filter for cleaning.

Please keep it in view: Avoid usage of typical household cleaners like washing powder or soap for filter cleaning. These products might have residues behind that will definitely change the water quality negatively in the long-run.

When to replace an outdoor whirlpool hot tub filter?

Not only is a replacement of a filter the option, but eventually your filter might need it.

Besides regular cleaning, time will slowly wear out the filter material that results in a degradation of its filtering properties. Therefore, the main cases where it should probably be replaced are as follows:

The material surface was damaged or got holes;

The arrangement of the filaments or pleats was somehow distorted;

Despite the cleaning efforts, the water flow was still insufficient;

Despite the cleaning, the water was not able to remain clean for a long time;

Unpleasant smell coming from the filter.

Under normal conditions, a top quality filter will last about 12 months. Proper maintenance of such filters can sometimes lead them to outlast the expected period with just a short replacement interval like 12 months turning them into over 18 months lifespan. Frequent use of spa hot tub, if any, might necessitate shorter intervals for filter replacing.

What are some tips one can adopt to decrease clogging of their outdoor hot tub filters?

Besides frequent cleanups, there are some simple habits you can follow on a daily basis if your intent is simply to avoid blockage in the filter of your outdoor whirlpool hot tub that will also prevent further blockage. 

First of all, before getting in the spa hot tub take a quick shower so that you remove a lot of the body oils and skin lotions that might get in the water and pollute it.

Secondly, covering the spa hot tub regularly prevents outdoor elements such as dust, insects, leaves and small particles from getting into the water and making the filter less efficient over the time.

In addition to that, one can monitor the level of impurities in the water regularly to prevent it getting to a point where there will be so much organic substances that cleaning will not be the first solution that comes to mind.

It is also important to have an idea regarding the water renewal schedule for your spa hot tub. If you neglect this for a certain time period, the level of impurities in your water will definitely go up, which will place a lot of burden on the filter system and keep it in a very bad state.

Frequently Asked Questions (FAQ)

How often should an outdoor whirlpool hot tub filter be cleaned?

Frequency of filter cleaning: it depends on various factors and as a guideline, the average recommendation for a household filter is once every 4–5 cleanings a quarter (i.e., once a week approximately) or once a month. However, this should also be taken into account when the filter is being used quite often or is located in an area with lots of dust, in which cases the recommendation is for an increased frequency of cleaning.

Could it be true that a clogged filter can result in a spa hot tub failing to get sufficiently heated?

Yes, definitely! A blocked filter decreases circulation of water which in turn means heat is not able to transfer as efficiently and as a result, spa hot tub heating can take much longer.

Can one just use the regular dish soap which is a common laundry detergent to clean off the outdoor spa hot tub?

The recommended practice is not to use such products because it is quite possible for them to leave behind a layer of foam in the water that might negatively alter the water quality while a specialty filter cleaner is a more ideal choice and can do such job for the filter cleaner.

Can low water flow in an outdoor whirlpool hot tub always be linked to a clogged filter?

In all honesty, it is quite possible. Besides a clogged filter, other factors that could interfere the spa hot tub with the pump, the piping and the intake would also need to be investigated.

So, how many times should you replace the filter in your outdoor whirlpool hot tub?

Replacing a spa hot tub filter is generally done once per year, depending upon frequency of usage, water quality and ‍‌‍‍‌maintenance.