Why is My Hot Tub Water Cloudy?

Cloudy hot tub water is a really common problem.  There’s nothing more disappointing than coming home from work looking forward to a nice relaxing soak in your hot tub to find that the water, rather than being sparkling clean and fresh, is all cloudy, milky and gloopy looking.

Not very inviting at all!

So, why is my hot tub water cloudy?  If your hot tub water is cloudy, check the filter is not clogged and is clean. You also need to check total alkalinity and PH of the water using test strips and adjust as necessary. Calcium hardness needs to be correct and you need to make sure that the sanitizer levels are not too low. The cloudy water could also be caused by the level of total dissolved solids in the hot tub water being too high.

The problem is that hot tubs,  with their relatively low volume of water per bather and their continuous high temperatures, are pretty much a perfect breeding ground for bacteria.  A lot of these bacteria are introduced to the hot tub via the human body and, left unchecked, they rapidly multiply and turn the water in your hot tub cloudy. Not only does the water look un-inviting it can actually cause skin rashes and potentially pass on diseases as well. However, bacteria and human dirt is only one of the many issues that could be causing your hot tub to have cloudy water.

Causes of cloudy hot tub water

The human body – If  nobody ever used your hot tub then the chances are that you wouldn’t have any problems with the clarity of the water at all.  Yes, one of the main causes of cloudy water is our own rather disgusting and filthy bodies. Whenever we get into the hot tub we bring with us a heady concoction of soaps, shampoos, moisturizers, shaving foams, suntan lotions, makeup, sweat, urine, feces and all sorts of other miscellaneous bits of dirt and debris.  These microscopic particles can soon start to mulch and fester into a rather disgusting green gloopy gunk.

Environmental debris – The other problem with dirt getting in the hot tub is when debris from the atmosphere falls into the water.  Whenever your hot tub cover is off, leaves, dust, seeds and all sorts of other airborne particles are going to be deposited in the water.  All this organic matter again just adds to the gloopy stew as it’s heated and swirls round the water in your hot tub.

Low sanitizer levels – We have just learned how organic debris, dirt and bacteria from our bodies can cause major problems with your hot tub water.  Your sanitizer’s job is to kill bacteria and to remove algae and foreign matter from the water to keep it clear and healthy.  If your sanitizer levels are too low then bacteria will build up and the water will become cloudy. More worryingly, it’s also possible that the water  could start to irritate your skin causing rashes and you will, or are also at increased risk of, picking up diseases from the water as well.

Incorrect water chemistry – Your cloudy water problem could also possibly be linked to incorrect water chemistry.  If your total alkalinity level or pH level is incorrect this can lead to increased scale formation and also cloudiness of the water.  The key here is regular maintenance, you need to check your water chemistry regularly and also, if possible, keep a record of the readings you get and the amount of chemicals you have used.  Once you have done this for a while you will hopefully start to recognize patterns in the behavior of your water and be able to predict any upcoming problems before they happen. Having the correct water chemistry is a foundation stone to having clear water as, if the alkalinity and pH levels are incorrect, the chances are that your sanitizer will not be as effective.

Calcium hardness levels – If there is a high level of calcium in the water this can also lead to increased scaling and cloudy water.  You can test for calcium hardness easily using test strips and adjust water as necessary.

Biofilm – Biofilm is an unpleasant and slimy bacteria that builds up and then coats the interior pipework and workings of hot tubs. If things get really bad you will notice slimy flakes floating in the water which will cloud the water and make it look really disgusting. You might find that the water becomes much more prone to foaming as well.

Metals in the water – You might not realize it but fairly much all water that comes out of domestic taps has some level of metal in it.  This sounds rather worrying but it’s totally normal. It doesn’t generally cause any problems but unfortunately can be an issue in a hot tub in that it can lead to damage of the internal workings of the hot tub and also staining of the hot tub shell.  In terms of helping to create cloudy water, metals in the water can quickly send your water chemistry out of balance meaning that your sanitizer will become less effective.

Pump problems – If you’re hot tub’s pump isn’t working, or is working inefficiently it means that the water isn’t being transported through the filtration system enough. This will obviously lead to water clarity problems. It could be simply that your pump isn’t on for enough time each day to filter the water properly. Check to see if your hot tub has an automatic system whereby the pumps can be switched on automatically for a couple of hours each day.  If not, you will manually need to run the pumps to make sure that the water is filtered regularly.

It’s also possible that the pump’s impeller might be blocked or not working. The pump itself could actually be running but it’s efficiency will be seriously impaired.  Again, this will mean that the water isn’t pushed through the filtration system vigorously enough and will possibly lead to cloudy water problems.

Filter problems – One of the primary reasons for cloudy water is that the hot tub filter has become clogged.  The filter’s job is to remove as many of the tiny particles of dirt from the water as possible.  This happens when the water is drawn through the filter and it captures the debris. Obviously, over time, there will be a build up and once this becomes too much the filter becomes ineffective. –

Air in the system – You probably know what tap water looks like when it’s got too much air in it.  Sometimes you can run a glass of water and it just looks cloudy for a few moments until the air escapes and the water clears. The exact same thing can happen in a hot tub if there is air in the system. Tiny air bubbles fill the water and give it a cloudy look.  It tends to not clear as the water in the glass does as the water in a hot tub is being continually circulated and also continually aerated.

If you suspect that your hot tub has an air leak you can try to find it yourself and to make a repair but it might be a good idea to consider calling out a specialist repairer.  It can be extremely difficult to find exactly where air is entering the system and a specialist will be able to sort out the problem much more quickly and effectively.

TDS levels – Once the level of total dissolved solids or TDS gets too high in a hot tub, to a certain extent, there’s not really much you can do to keep the water from becoming cloudy.  Basically, the water has become completely saturated with debris and particles to the extent that is not far off becoming a thick green soup! It’s a bit like filling a glass of water with salt or sugar. For a certain amount of time the solids will dissolve in the solution but, once the water becomes saturated, the salt or sugar won’t dissolve and just sits at the bottom of the glass. Its’ the same in a dirty hot tub. There comes a point where the water gets saturated with debris and it just floats around and makes the water look cloudy and dirty.

How to fix cloudy hot tub water

As soon as you notice that your water is cloudy or not as clear as it usually is then you need to take action.  Not only is it unpleasant sitting in cloudy water it can also present a significant health risk to you as well. It’s possible that you might be at increased risk of catching an infection or developing a skin rash. You are also putting yourself at risk of catching some unpleasant diseases such as Legionnaires disease which can be present if the legionella bacteria is allowed to grow in your hot tub.  Not only is cloudy water bad for you, but it also puts unnecessary stress on the hot tub components as well. If your filter is becoming blocked with particles then the pump will have to work harder and the heating element will need to work harder as well to maintain the temperature. Both of these issues put strain on the system and also make your hot tub significantly less economical to run.

If you have cloudy water in your hot tub here’s what to do.

Add clarifier – Clarifier is a chemical that you can add to your hot tub that will possibly fix your cloudy water problem quite quickly. The polymers in the clarifying chemical create a bond between the dirt particles in the water and make them clump together. Before they were clumped together the dirt particles were too small to be caught by the filter in your hot tub but, now that they are in larger groups, the filter catches them and the water should instantly look clearer. It’s important that after using a clarifier you thoroughly clean your filter otherwise it will quickly become less effective and will put a strain on the pump as it tries to pull water through it.

A good clarifier will not affect the pH level of the hot tub water and will give your water as satisfying sparkly shine.  Some people like to add clarifier on a weekly basis even to a clean hot tub to get this lovely sparkling look. However, if you have a cloudy water problem using clarifier is only a short term solution. It might make the water look clearer for a while but you need to sort out the underlying problem.

Check the filters – One of the most common causes of cloudy water in hot tubs is that the filters need cleaning or replacing. Take your filter or filters out and,  in the first instance, check to see that there isn’t any large pieces of debris clogging the filter up or that the filter is damaged.  Once you have done this use a hosepipe to thoroughly clean the filter aiming the jet between the pleats and all of the gaps to make sure that you remove as much dirt as possible. You can use a wand attachment on the end of your hose if you want to make this job a little bit easier.  Once you have thoroughly flushed through the filter with water check that it looks clean. If you are still not happy then you should give it a soak in a filter cleaning solution for 24 hours in a bucket. Again give it a thorough rinse through with clear water from the hosepipe before inspecting the filter again.  If it still doesn’t look clean than it might just simply be time for a new filter.

Remember you can avoid filter problems by regular maintenance. Every 1 to 2 weeks you should be taking the filter out and giving it a thorough rinse and every 2 to 3 months you should be giving it a 24 hour deep clean in a chemical rinse.  Filters also need changing on an annual basis. If you keep to this schedule then you should find that a lot of your cloudy water issues don’t reappear. Bear in mind that if your hot tub is heavily used you will probably need to clean and/or change the filters more frequently.

Check the total alkalinity and pH level – You will need some hot tub test strips and also some alkalinity and pH level balancing chemicals to carry out this job.  You should really check your alkalinity and pH at least on a weekly basis. If you are doing it less frequently than this then this could potentially leads to all sorts of problems.

Test the alkalinity first followed by the pH. You are looking for a total alkalinity level of between 100 and 120 parts per million and a  pH level between 7.4 and 7.6.

If you need to make adjustments to either the alkalinity or the pH you will need to add balancing chemicals.  Check to see how many gallons of water your hot tub holds before consulting the chemical’s instructions to see how much to add.  Sprinkle the chemical over the water surface with the jets on so that’s the chemical gets distributed evenly and wait 30 to 60 minutes before retesting.  Repeat as necessary.

If you need to raise the alkalinity then use a hot tub alkalinity increaser.

If you need to lower the alkalinity then use a hot tub PH decreaser.

If you need to raise the PH then add a hot tub PH increaser.

If you need to lower the PH use a hot tub PH decreaser.

Check the calcium hardness – Again you can check your calcium level using a hot tub test strip kit. The ideal level of calcium hardness is somewhere between 175 to 250 parts per million.  If you’re level is below this then it’s easy to add the calcium hardness chemical to increase the level. However, if your calcium hardness level is significantly above this then, unfortunately, there isn’t really an effective way of reducing it or taking it out of the water.  The only thing you can do is to drain and refill your hot tub using a filter on your hose to reduce the amount of calcium in the water before it actually gets into the hot tub in the first place.

Check your sanitizer level –  Make sure that your sanitizer level is correct.  If in doubt it’s worth giving your sanitizer a boost and,  assuming that you are using chlorine, adding chlorine until you reach a level of between 5 and 8 parts million. Wait for at least an hour until the chlorine level has reduced to a safe level of between 2 and 4 parts per million and do not enter the hot tub until this level is reached.

If you’re sanitiser level is already between 2 and 4  2 million then it might be a good idea to use a good shock treatment to see if that clears the water.

Add a metal sequestrant – If after having done the checks above you still have discolored water then it’s possible that you might have metal deposits in it.  This is problematic as metal is oxidised by chlorine so when chlorine is added to the water the water becomes discolored. You can help prevent this problem in the first place by filtering the water when you put it into your hot tub you by using a hose filter. But, if you want to have a go at reducing the amount of metal in the water that already in your hot tub, then you need to use a metal sequestrate chemical.

Check the TDS levels – If everything else fails to clear up your cloudy water problem then your final course of action is to check the total dissolved solids or TDS levels in the water.  You do this again simply by using a test strip and dipping it in the water. If the TDS level is over 1500 parts per million it means that your water is completely saturated and your only course of action is to drain and refill the hot tub with fresh water and start again.

Drain and refill your hot tub – Draining and refilling the hot tub should be part of your regular hot tub and maintenance schedule and most hot tubs need this doing every 3 months or so.  You might find that if your hot tub is heavily used then you need to do this more frequently. Alternatively, if you don’t use your hot tub a lot or you have an extremely high tech filtration system then you might be able to do it less often.  However, if you have a cloudy water problem and you really can’t get rid of it with any of the techniques above then your only course of action is to do a complete drain, clean and refill of your hot tub.

To prevent cloudy water problems reappearing before you drain a hot tub add a flushing solution to the water and run the jet to flush out any dirt from the system.  After you have completely drained the hot tub it’s really important that you give the shell a thorough clean. Any algae or bacteria present needs to be removed so that it doesn’t continue just living in the new water and contaminating that.  When you refill a hot tub remember to use a filter on your hose so that any excess calcium of metal can be removed from the water.

How to keep your hot tub water from becoming cloudy

Obviously, prevention is better than cure and the best way to avoid having cloudy hot tub water is to follow the steps below starting with a drain and fresh fill of water in your hot tub.

Flush out the system –  Before you drain the water out add a flushing solution to the hot tub and run the jets for 20 minutes or so to circulate the solution and flush out the dirt.  This is really important as dirt and bacteria can accumulate in the pipes and components of the hot tub and the only way to really clean them thoroughly from the inside is to use the flushing solution.  

Clean the hot tub – Drain the water from the hot tub and give the whole hot tub shell a really thorough clean using a special cleaning solution. Pay particular attention to the area around the water line and around the jets to make sure that there isn’t any algae or dirt build up.  Once you have thoroughly cleaned the shell wash it with fresh clean water to make sure that there is no residue left.

Fill with filtered water – When you refill your hot tub with water use a  filter attachment on your hose. This will remove any excess calcium and metals that are present in the water.  It’s really difficult to remove these once they’re in the hot tub and they can be very problematic so it’s a good idea to start off with filtered water in the first place.

Stick to a maintenance schedule –  Probably the most vital step in keeping your water clear is to stick to a regular maintenance schedule.

Weekly –  Check the pH level and alkalinity at least every week and also shock the hot tub after each use, or at the very least on a very regular basis. You also need to check your sanitizer level and adjust as necessary at least once a week as well. Most hot tubs will need their filter inspecting and cleaning on a weekly basis too.

Monthly –  In addition to the weekly tasks above you should give your hot tub filter a thorough deep clean every month.   Soak it in a bucket with a deep clean chemical overnight and then give it a thorough clean in fresh water before putting it back in position.

Quarterly –  As a general rule, most hot tubs need a complete drain and refill every 3 months or so.  It’s tempting to try to make the water last longer as this is quite a big job, but remember that you are at risk of getting cloudy or smelly water if you don’t change it frequently enough. You can also risk contracting rashes and illnesses yourself as well as damaging your hot tub so it pays to make changing the water  a regular quarterly habit.

Use the cover –  Remember to replace your hot tub cover whenever it isn’t in use to prevent dirt and debris from the environment from getting into the water.  You also need to thoroughly clean and dry out your cover on a regular basis to keep it in good condition and prevent the buildup of bacteria and algae.

Shower before going in the hot tub –   Our bodies or one of the main sources of dirt and bacteria that contaminate your hot tub’s water.   You can go a long way to helping prevent cloudy or dirty water by having a shower before entering your hot tub.  The aim is to remove as many bodily fluids, cleaning products and makeup as possible before getting into your hot tub. If you wash with shower gel or soap or use any shampoo in the shower, thoroughly wash your hair and body with clear water afterwards to avoid taking any residue into the hot tub with you.

Summary

Cloudy, dirty or smelly hot tub water is not only extremely unpleasant but can be potentially dangerous as well.  Dirty water harbors all sorts of bacteria and algae, some of which can pose serious health risks. At the very least it’s possible to develop a skin rash after being in contact with dirty hot tub water.  Not only this, but dirty hot tub water would put extra strain on your hot tub’s inner workings and make it significantly less efficient. In the long term this can possibly cause components to wear out prematurely.

Cloudy water is caused by dirt and can, to a large extent be avoided by keeping hot tub cover on as much as possible and also by washing our bodies thoroughly before getting into the hot tub.  These two things alone will prevent a lot of foreign matter from getting into the water. However, inevitably all hot tubs will get dirty eventually which is why it’s really important to keep on top of your water chemistry to combat this. To a certain extent, once the water is cloudy or dirty, you have lost the battle. It’s much better to stick to a regular maintenance schedule which, if carried out properly will prevent the water becoming cloudy in the first place. All hot tub water will need changing eventually but proper maintenance will keep the water clear and fresh for much longer.

If you have a cloudy water problem and don’t want to change the water then you can try adding a clarifier in the first instance which might provide a temporary fix.  Also, try giving the tub a good shock treatment and making sure that the sanitizer lever is as it should be. Filters need to be clean and you also need to make sure that the total alkalinity and pH level of the water is correct.  Remember that once the water gets to a TDS level of 1500 parts per million or more than there really isn’t anything you can do apart from draining hot tub and starting again with fresh water.