How to Fix & Prevent Cloudy Hot Tub Water

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Is cloudy water keeping you out of your tub? Having hazy or murky water is a common hot tub issue. Luckily, preventing it is easy. I will provide you with some great tips on how to remedy cloudy water in your spa, and keep it from coming back!

Cloudy hot tub water

Treating Cloudy Water

“There are several different reasons for spa water to become cloudy, and each requires a slightly different treatment.”

-Mark, SpaDepot.com Hot Tub Expert

Some basic reasons for cloudy water in your hot tub:

  • Out of balance water
  • Low sanitizer level
  • Excessive contaminants
  • Clogged or worn out filter
  • High TDS levels

Out of Balance Water and Low Sanitizer Level

Test your water with easy to use test strips

Finding out if your hot tub water is out of balance or has a low sanitizer level is as easy as pulling out your test strips.

  1. Allow your spa to circulate for a minute or two.
  2. Follow the directions on your test strip bottle for dipping and comparing your results to the color chart.
  3. Add the chemicals that are necessary to restore your water balance or sanitizer to its proper level.

WAIT 5 – 10 MINUTES WHEN ADDING DIFFERENT CHEMICALS! Adding too many chemicals at once can create cloudy water that takes days to clear and is often difficult to balance.

Excessive Contaminants

Hair products, skin products, and detergents can all contribute to cloudy water.

Preventative Tips:

  • Before entering the tub, rinse off any lotions, hair sprays etc.
  • If you have long hair, you can put your hair up to keep it out of the water.
  • Rinse out your swimwear if you have washed it with detergent.

Remedy:

If your water has already been contaminated with any of the above, you can shock your water and use a natural clarifier to effectively clear-up the cloudiness.

Oxy Spa
These two product options will act instantly to rid your hot tub water of residual soaps, lotions, oils, hair spray and other organic material build-up.

Clogged or Worn Out Filters

A clogged or worn out filter can fail to trap contaminants and also put strain on your spa pump. To avoid a potentially costly mishap:

  • Filters should be rinsed every 2-4 weeks
  • Every 3-4 months, or with every water change, you should pre-rinse your filter and soak it overnight in a non-foaming filter cleaning compound. Rinse the filter again and allow it to dry before returning it to the hot tub.
  • Hot tub filters should be changed annually or sooner if you notice significant wear or damage.

Dirty and worn spa filter

High TDS Levels

My Water is Still Cloudy… Hot tub water older than 3 – 4 months accumulate high TDS levels that cause persistent cloudiness. If none of the steps above are getting your water back to crystal clear, it’s time to flush, drain and refill your tub.

Keep in mind: If you drain and refill your tub, but do not use a system flush, or use a dirty or old filter cartridge to filter your new water, it will get cloudy again. Don’t waste your time – follow these simple steps:

  • Flush your system and remove oily residues and deposits from the inside of your plumbing system.
  • Check that your filter is not clogged or full of debris that will release contaminants into your fresh water.
  • Using a fill filter helps to eliminate impurities that could be clouding your water, and fills your spa with higher quality water.

Prefresh fill filter

If your hot tub water is green and cloudy, please see our Green Hot Tub Water  blog post for more information.

Still have questions about hot tub maintenance or cloudy water? Post a comment below and we will help!

74 comments

  1. Hey there! Someone in my Facebook group shared this site with us so I came to give it a look. I””m definitely enjoying the information. I”m bookmarking and will be tweeting this to my followers! Terrific blog and superb style and design.

    Like

  2. I use Nature 2. I recently bought new filter from you about 2-3 months ago, but now my water has a greenish tint, and is cloudy, both which were problems before. I use dichor as the sanitizer, and occasionally the Oxy-Spa, along with Defender and a clarifier. My water is once again cloudy with a slight greenish tint, probably from the silver in the Nature 2. My alkalinity is high, and my pH is about 7.8. The mono-whatever reading is in the good range. It””s too darned cold (27) to get out there and change the water. Any suggestions?

    Like

  3. Hi David,
    Thank you for your comment. If your hot tub water is older than 3-4 months, the Total Dissolved Solids level becomes very high and will cause cloudy and discolored water. If it is too cold in your area to do a full drain and refill, it is a good idea to drain at least 1/4 – 1/2 of the water and replenish with fresh. This will buy you some time until a total drain and refill can be done. Another cause of water discoloration is when metal parts in the equipment begin to corrode. This occurs when the pH or Alkalinity levels are consistently out of balance. Please let me know if you have any additional questions.

    Thank you,
    Kaisa
    SpaDepot.com

    Like

  4. water is clear umti; i turn on the pumps. After 1 minute the water is cloudy and foams forms on top. Tube is new two weeks old. i have had the water tested. everything looks ok.

    Like

  5. Hi Terry,
    Thank you for your comment.
    Cloudiness and foam is usually an indication of excess contaminants (such as soap residue from swim suits, lotion or hair products). These will not show on your test strips. The best way to get rid of this is to use a non-chlorine oxidizing shock, such as Oxy Spa. Here is a link to this item: http://www.spadepot.com/shop/Oxy-Spa-Non-chlorine-MPS-Shock—2-lbs-P93C43.aspx
    The other reason why you may be experiencing cloudiness and foam is if your pH level is too low. You can use pH Increaser to raise this.
    I hope this is helpful. Please let me know if you have any additional questions.
    Thank you,
    Kaisa
    The Spa Depot

    Like

  6. I have never seen a filter that attaches right to the hose. I clean my hot tub out about once a week, but it doesn’t seem to take long for it to get foggy again. It would be really nice if a filter like this would help with
    that.

    Like

  7. Hi Lacey,
    The Pre-Filter could help. Usually foggy water is also caused by dead organic material in the tub. Using oxidizing shock will help clear it up if this is the case.
    Thanks,
    Kaisa
    The Spa Depot

    Like

  8. Good morning. I have had my spa for a week. My ph is really high. I gave used almost half bottle of ph down and still no luck on getting it down now water is very cloudy can still see bottom but not well

    Like

  9. Thanks for all the tips and solutions I have recieved alot of great products over the years from you guys, very happy customer and will keep coming back.

    Like

  10. We just bought our first hot tub and filled it. We checked the levels and noted the ph was too high and the calcium was too low. I added the initial amount of chlorine, added some stuff to reduce the ph and added stuff to increase the calcium. Once I added the stuff for the calcium, the water turned cloudy. All of the levels are within the “ideal” ranges and I have already added a non-chlorine shock and put in the Nature2. I haven’t tried adding a natural clarifier yet but I am wondering why the water is still cloudy? Any suggestions or advice would be great!

    Like

  11. We recently bought our first hot tub. We used a filter on the end of our hose to fill it. We tested the levels and noted the ph level was too high and the calcium level was too low. We put in the chlorine (.05ppm), reduced the ph and when we added the stuff to increase the calcium, it turned the water cloudy. All levels at the time were within the “ideal” ranges. We also put in the Nature2 stick and some non-chlorine shock. I haven’t tried a natural clarifier yet, as I was hoping to solve the problem without adding more chemicals. Any thoughts or suggestions would be great!

    Like

  12. Hi Carrie,
    Don’t worry, this is normal! Calcium increasing products do cause initial cloudiness. Just run your filtration cycle for 24 hours and rinse out the filter every 2-4 hours. The cloudiness will subside.
    I hope this is helpful. Please let me know if you have any additional questions.
    Thank you,
    Kaisa
    SpaDepot.com

    Like

  13. I just refilled my swim spa two weeks ago. I also put in new filters. The water started to get cloudy 2 days ago. It’s very blue but cloudy, I took in water sample everything was normal but calcium level was low so I added calcium and later on I put in non oxidizer shock. I waited 4 hours or so and rinsed both filters out. I was hopeful that over the night it would clear up but I just checked it and it is still cloudy, any suggestions?

    Like

  14. Hi April,
    I would be happy to help. Can you tell me what chemicals you’ve added to the water since you refilled?
    Usually cloudy water would indicate an excess of dead organic matter. But I can help you determine if that is that case based on what how you’ve treated the water so far.
    Please let me know.
    Thank you,
    Kaisa
    SpaDepot.com

    Like

  15. I just bought a used Free Flow LS200DX 250 gallon tub and bought the Cleanwater Blue package. We filled the tub six days ago following the Clearwater Quick Start Guide to the letter. The last two days it’s been cloudy so I added 1 tsp diclor and the Sea Clear clarifier yesterday and checked the TA and PH. Still Cloudy. I called tech support to try and find out how to filter for longer periods and they said I have a “Balboa” system with a one speed pump for filtering and temperature (It only filters when we turn on the jets or it has to get up to temp). There’s two of us using it and it’s been filtering at least three hours a day. He said the copper system won’t work with my tub and start using diclor everyday and the non chlorine once a week. Hmmmmm??? He also had never heard of Cleanblue! My copper was a little low when I tested it today and I also was using 2.5tsp of OXY SPA for 250 gallons. Would appreciate your thoughts so I don’t have to go to diclor.
    Thanks!!

    Like

  16. Hi Bernadette,
    Thank you for sending this message! The information you received from Free Flow was incorrect, Cleanwater Blue will work great with your spa. Three hours of filtration a day should be just fine. Cleanwater Blue actually disperses very efficiently throughout your spas water with very little water flow.
    I believe the cloudiness may have been caused by not using enough shock. I would recommend using about 1-1/2 tablespoons after each use. That should prevent the water from getting cloudy. To accelerate clearing up the current cloudiness, you might consider draining about 12” of the water and refilling. If the water is still a little cloudy tomorrow morning, another teaspoon of Dichlor should clear it up nicely. Thanks again for checking with us, and please let me know if you have any other questions!
    Mark
    SpaDepot.com

    Like

  17. Thank You Mark! It’s clearing up a bit now. I pulled out the filter and it was really dirty, greenish but came off with a garden hose. Did I read somewhere about copper attatching to the filter and turning it green?
    Really appreciate your great customer service!
    Bernadette

    Like

  18. Hi Bernadette,
    Great! If too much Cleanwater Blue is added to the water, it can turn the filter a little blueish-green. If that happens it will not cause any problems. Thanks again and please contact us any time you have questions!
    Thanks again,
    Mark
    SpaDepot.com

    Like

  19. I have a spa that is 20 years old and still runs great. My problem is cloudy water after a month. I use to use Baqua spa and switched to Leisure Time free. I always rinse filter after use. the spa only holds approx. 250 gals. Any ideal on how to prevent cloudy water?

    Like

  20. Hi Perrin,
    I would recommend increasing the amount of shock you use each time, and clean your filter out monthly with a filter cleaner, rather than cleaning it out after each use. We have filter cleaners available here:
    http://hot-tub-supplies.spadepot.com/search#w=filter%20cleaner
    Following these steps could help reduce or eliminate the cloudiness. Although you switched from Baqua Spa, you are still using a biguanide system. We recommend using a non-biguanide sanitizing system. We have a few different choices available here:
    http://www.spadepot.com/shop/Alternative-Sanitizers-W17.aspx
    I hope this helps!
    Thanks,
    Mark
    SpaDepot.com

    Like

  21. I use my hot tub daily and have no problem with the water being clear.
    In the last month we have gone away for two different weekends, Friday night to Sunday night and the water is cloudy each time we came home. The hot tub has a one pump that runs all the time moving the water and I have put chlorine in before we left. Is there something I can do to stop this from happening while on vacation or out of town a few days?

    Like

  22. Hi Mark,
    The tub should be drained and refilled every 3-4 months. Using the tub daily and always having clear water means that you do an excellent job taking care of the water chemistry, but this requires adding chemicals. Regular chemical application raises your total dissolved solids level. In three to four months the high TDS levels (particulate build up) start to cause cloudy water, and can make managing the pH and alkalinity levels more difficult.
    I also recommend soaking and cleaning your filter monthly. It is a very good idea to use a filter cleaner like Power Soak when cleaning your filter: http://www.spadepot.com/shop/Power-Soak-Filter-Cleaner-P779C57.aspx. Be sure to replace your filter cartridge annually.
    If you do take good care of your filter and drain your spa every three months, adding more chlorine prior to leaving for the weekend should prevent the water from clouding up.
    Hope this helps!
    Thanks,
    Mark
    SpaDepot.com

    Like

  23. HI
    We have a 200 gal spa and we have used clearwater blue system for the last year with very little problem. However, I’m currently having a hard time getting the copper level to respond to the algicide/bactericide. The PH and TA are within the recommended range before I added the cleanwater blue. The water looks clear but has a slight oder. I rinse and clean my filter every two weeks and rotate out every 3 month with a soaked/clean, dry one when I drained and cleaned the spa. The spa isn’t do to be drained for another month. I had to increase the TA a couple of times. I have used dichlor shock hoping it would help. I also use of non-chlorine shock regularly. What should I try next.
    Thanks,
    Dana

    Like

  24. Hi Dana,
    Thank you for your comment. I am happy to help.
    “I’m currently having a hard time getting the copper level to respond to the algicide/bactericide.”
    Could you please clarify what issue you are having? The copper is the algicide/bactericide (The Blue box).
    Thank you,
    Kaisa

    Like

  25. I just filled my hot tub. New filter, etc. I added mineral out as always. I tested the water and showed very high alkalinity and ph. I added 8 oz. of ph down. Water turned very cloudy within 8 hrs. Still very high readings. I do have very hard water in my area. So, I just diluted 1/2 oz. muratic acid and added it.

    Like

  26. Hi Don,
    Thank you for checking with us! The cloudy water was likely caused by the mineral out and pH balancing chemicals being added too closely to one another. At this point I recommend setting the filtration cycles on your hot tub to continuous, and waiting for the water to clear up. This would usually take about 2 days. The alternative would be to drain the water and refill the tub. If you do drain and refill, be sure to give 4-6 hours (or more) between the mineral out and the other water balance products.
    Hope this helps, and please let us know if you have any other questions!
    Thanks,
    Mark
    SpaDepot.com

    Like

  27. Great site. You mention – Flush your system and remove oily residues and deposits from the inside of your plumbing system. – How do you flush the inside of the plumbing?
    Thanks.

    Like

  28. Hi All,
    we have a spa (~860 litres) which went cloudy overnight. All chemical levels are perfect. The water is less than one week old and the filter is new. We used it last night and put the cover on over night (every night) and when we removed the cover this morning it was cloudy. Can the cloudyness be caused by the warm weather and warm water (we live in Australia and summer is just starting here)? Should we stop putting the cover on over night?

    Like

  29. Hi Allan,
    Thank you for checking with us. If your filtration cycle is set too low, that could cause the cloudy water. Your filtration cycle should run for about 2 hours twice per day. Be sure to add oxidizing shock to the spa after each use. This will break down dead organic matter and help to prevent cloudiness.
    Having your cover on or off will not make any difference with the clarity of the water, and it is best to leave your hot tub cover on when not in use to prevent debris or animals from entering the tub.
    I hope this information helps, and please let us know if you have any other questions.
    Thank you,
    Mark
    SpaDepot.com

    Like

  30. recently drained/refilled my companies 600 gallon hot tub and over night it became very dark green and cloudy with people using it, when i came in the bromine was basically non existant. i have used non-chlorine oxidizing shock as wells as raised the bromine to 10 and stabilized it back down to 5. Now all of my levels are fine, brom. 5, p.h. 7.2, alk. 120, c.h. 220, the color cleared up mostly its just slightly green/yellowish but is cloudy still. I’m not sure what step to make next, need help a.s.a.p.! i was thinking maybe more stabilizer would help make it less cloudy? any ideas anyone. thank you, George

    Like

  31. Hi George,
    Thank you for posting your questions. At this point, I would recommend cleaning out the filter, and increasing the duration of the filtration cycle. If the filter is older than one year, it’s best to replace it. Adding another dose of shock should help remove the yellow/greenish color.
    I hope this helps, and please let me know if you have any other questions!
    Thank you,
    Mark
    SpaDepot.com

    Like

  32. My water was nice and clear then over a course of 3 days it started to get foamy then turned very brown this is the 2nd time i have had this happen i use bromine can you help me i would like not to have to drain and refill every 2 weeks also i get a lot of brown slime arould the water line any help would be great thanks

    Like

  33. Hi Barry,
    If you have well water, the brown may be cause by rust or manganese in your source water. If the ring around the water line is slimy, that would be caused by not enough sanitizer in your water. To prevent the brown from coming back, it would be a good idea to use Metal Free each time you refill, we have Metal Free available here:
    http://www.spadepot.com/shop/Metal-Free-Spa-Scale-Stain-Control-16oz-P97C635.aspx
    To prevent the sliminess, be sure to test your bromine level to make sure it’s at the proper level, and be sure to shock your hot tub with 2 tablespoons of non-chlorine shock weekly. If you follow these steps and the problems continue, follow this decontamination process to get rid of it completely:
    http://www.spadepot.com/spacyclopedia/spa-contamination.htm
    I hope this information is helpful, and please let me know if you have any other questions!
    Thank you,
    Mark
    SpaDepot.com

    Like

  34. Hello. I have had my spa (CLS 738L) for 5 months and water has been blue-ish and cloudy lately. Levels test fine, so I decided it’s time to drain and refill the water. I read in my manual I need to replace the eco pur filter every 6 months and the regular filter once every 12 months. I’m confused on which is which. Is the cartridge (the longer one) the eco pur one? Or is the shorter one (the one that screws in on top) the eco pur? I want to make sure i’m taking care of it so it doesnt cloud quickly again. Thanks

    Like

  35. Thanks for the quick reply Bonni. I ordered the correct one then, thanks for the clarification. Seeing as this is my first hot tub, I’m sure I will have more questions in time. Thanks again!

    Like

  36. Hi Dustin,
    Thank you for your question.
    The Eco Pur filter is the smaller one that goes on top and needs to be replaced every 6 months. The regular filter (the longer one) needs to be replaced every 12 months.
    Please let me know if you have any further questions!
    Thanks,
    Bonni
    SpaDepot.com

    Like

  37. Please help me…
    So we have had out hot tub for almost 2 years. I just went out to do a check on things and the alkalinity was very low… almost 0?!? I brought it back up and then when I went out to look (30 minutes later) the water went from crystal clear to having a distinct blue tinge to it. The PH was high as well, I have put in some PH minus and will add chlorine after as well. We use Lithium (not chlorine or bromine). We had this problem a few months back but I put new water and a new filter in about a month ago. Previously the water was about 4-5 months old.

    Like

  38. Hi Micah,
    I’m sorry you’re having trouble with your water! Lithium is actually lithium hypochlorite, which is an non-stabilized form of chlorine shock used in pools with vinyl liners.
    Lithium has a high pH, and with your total alkalinity as low as it was definitely explains the high pH! Alkalinity is the buffering capacity of the water, or how much the pH will change when you add other chemicals to it. The blue color was probably due to the changing pH reacting with something in your water, like metal.
    I would recommend switching to a sanitizer meant for spas, like Cleanwater Blue or Nature 2. Here’s a link to our article on spa sanitizers:
    https://hot-tub-blog.spadepot.com/2015/04/what-is-a-hot-tub-sanitizer-and-which-sanitizer-is-the-best.html
    Keep in mind that spas need to drained and refilled every 3-4 months. This is because the Total Dissolved Solids (TDS) are high enough that chemicals are no longer effective. If you are unsure if your spa should be drained at the 3 month mark, try testing it with TDS test strips to see where your levels are:
    http://www.spadepot.com/shop/AquaChek-Total-Dissolved-Solids-TDS-Test-Strips-P846C60.aspx
    If you are struggling with pH or other hot tub issues, you can always email our experts at help@spadepot.com or call (800) 823-3638. They can also suggest a new sanitizer based on your usage and maintenance preferences.
    Thanks,
    Sarah
    SpaDepot.com

    Like

  39. Hi
    I just bought an intext inflatable hot tub. Used it once. I just put clorine in it but accidentally got still rain water from the cover into the hot tub. Now the water has a green color. Will the color change will the filters clean the water. Help
    Thanks
    Ray

    Like

  40. Hi Raymond,
    The green color is most likely the metals in your water reacting with the chlorine you added, and is a common issue. Adding a metal stain control like Metal Free will keep the water from changing color when you add chlorine or other chemicals.
    Additionally, using a PreFresh hose-end filter to fill your spa will eliminate some metals before they reach the tub.
    PreFresh filter: http://www.spadepot.com/shop/PreFresh-Spa-Pool-Water-Fill-Filter-P784C632.aspx
    Metal Free: http://www.spadepot.com/shop/Metal-Free-Spa-Scale-Stain-Control-16oz-P97C635.aspx
    Let me know if you have any other questions.
    Thanks,
    Sarah
    SpaDepot.com

    Like

  41. Hi
    Thank you for this information, just got my hot tub 5 days ago so still trying to work it out, thanks for the advice and guidance fingers crossed I get sparkling water after shock treatment :0) will be using this site regularly I think
    Thanks

    Like

  42. Hi Christine,
    Have you balanced the pH and alkalinity yet? Sometimes pH balance issues can cause cloudiness, and adjusting those levels will clear your water up after 24 hours.
    If that doesn’t work, try adding a dose of dichlor shock to your spa. This chlorine shock clears water quickly, but make sure to leave your cover off while shocking.
    http://www.spadepot.com/Dichlor-Sanitizing-Granules-2-lbs-P617C43.aspx
    Let me know if you need more help!
    Thanks,
    Sarah
    SpaDepot.com

    Like

  43. My spa water was clear, however when I tested with strip showed hardness was low as well as bromine. Added correct amount of calcium hardner and water instantly turned cloudy. Why could possibly be causing this? I’ve had this problem before and resolved it by removing and cleaning filter repeatedly until water was clear again. Just purchased new house 12/15 and never had hot tub or pool so I’m new at this and could use some guidance. Thank you in advance.

    Like

  44. Hi Chaz,
    Calcium increaser can raise the pH of your hot tub, and high pH can cause cloudiness. Retest your water and adjust the alkalinity and pH, and your water should clear up. If it doesn’t clear right away, a natural clarifier like Sea Klear should fix the problem.
    http://www.spadepot.com/SeaKlear-Natural-Spa-Clarifier-16-oz-P99C635.aspx
    If your bromine is low and you know your tablets or cartridge is emitting bromine, try shocking the water with non-chlorine shock. This will free up the bromine already present in the water.
    http://www.spadepot.com/Oxy-Spa-Non-chlorine-MPS-Shock—2-lbs-P93C43.aspx
    Let me know if you need any more help.
    Thanks,
    Sarah
    SpaDepot.com

    Like

  45. We drained and refilled out hot tub 2 weeks ago and it has been cloudy ever since. All the levels are in range and we have put a new filter in also. Also shocked it. The water was perfect before draining and filling. We added Calcium alk up and shocked it now a few times and still cloudy. Whats next??

    Like

  46. Hi Sharon,
    Excess hardness and high pH can cause cloudiness. Try testing for hardness and pH again to see if too much calcium or Alkalinity increaser were added to the water.
    If everything is still within the correct range, try using a clarifier to combine the small particles causing cloudiness and deposit them on your filter. Make sure to thoroughly clean the filter after using clarifier. We love Sea Klear Natural Clarifier:
    http://www.spadepot.com/Sea-Klear-Natural-Clarifier-for-Spas-32oz-P671C635.aspx
    Thanks,
    Sarah
    SpaDepot.com

    Like

  47. When I changed my spa water it was clear for about a week or maybe two and then went cloudy. I’ve never had this problem before. The one change is I added a water softner to my house (well water) could this be a problem?

    Like

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