I have recently purchased new swamp cooler at home. It was working fine for a 3 days then the water in it started to stink , But I used to remove water completely every day and fill it with new supply of water but still the problem persist and I cannot open the cooler to wash it. Can anything be done to prevent that odour?

  • If your cooler is contaminated enough for the water to start stinking so soon, do you trust the water quality? Better return the cooler to the seller and cool your water in a different way in my view. Bottles in the fridge work well.
    – Willeke
    Commented Apr 17, 2017 at 9:02
  • @Willeke No it is not actually water cooler. It is used to decrease temperature of room , like Air Conditioner. Or I think it is called as swamp cooler . Commented Apr 17, 2017 at 9:18
  • Maybe "Desert cooler" is a synonym
    – DS R
    Commented May 7, 2017 at 13:13
  • 1
    Check the owner's manual and if it has no objection, then put some lemon juice in the water to inhibit mold. You could use vinegar but that would not smell very good either. Commented May 8, 2017 at 1:22

6 Answers 6


Usually, you need to change the water in 4-5 days but if it stinks that bad as you said then there are many reasons for it:

  • Might be the water you are using is not good.
  • The Pad used in water are not clean, this might be the major reason it stinks. You can change your pad or better if available honeycomb pad is good for the cooler you can go for that too.

Changing pad would be costly so better you can search for cooler odor purifier liquids, they are present in various odors khas, rose etc. They are easily available at any nearby cooler shop.

Hope this would be helpful for you.


Swamp coolers I've used in the past didn't hold onto water long enough for it to develop algae and bacteria growth that would smell. The evaporation that cools the air requires making up water -- in a dry climate, at the rate of several gallons per day. This is often an automatic process, governed by a float valve inside the cooler and supplied by a line connected to a faucet or water pipe side tap, but turning off the water supply should result in the cooler running dry in a few hours, at most.

If your swamp cooler isn't requiring this amount of water added, it's likely that it's also doing little or nothing to cool your air due to high ambient humidity. If this is the case, a swamp cooler is the wrong kind of air cooling system for your climate, and you'll have to invest in a refrigerant based system.

If a swamp cooler is all you have, you might shop for products intended to kill algae and bacteria in small fountains -- they should work as well in a swamp cooler. Whether they're "safe" for a high evaporation system is another question, but they're unlikely to be worse than breathing bacteria growing in the water and then being shot into the air (this is the usual source of Legionnaires' Disease, among other unpleasantness).

  • No it is actually working well , sometimes I need to wake up at 3 /4 am to turn it off , because room becomes so cold. I have only problem with odour. Commented Apr 17, 2017 at 12:50

Removing the water daily will not significantly decrease the bacteria unless you thoroughly clean it also. I had a friend who had a similar issue with a "water wall" in a retail environment. Per my suggestion she experimented with small amounts of bleach added to the water until she found a balance between killing the flora and fauna, and killing her customers.


It is possible that some creature might have died inside the cooler, possibly because of the blades. It could be a lizard. Then when its body decays, a horrible smell results. Such a situation is often mistaken to be due to water odour. But freshly filled water should not smell in a day. You'll have to get the cooler opened to inspect it.

  • No , it is certainly not that. Commented May 7, 2017 at 13:16
  • Are you sure? Because a bad smell means something​ is rotting/decaying because of bacteria. And water should not smell in a day, that too when it is circulating, i.e. in motion.
    – DS R
    Commented May 7, 2017 at 13:25

Add fluoride. It is present in toothpaste and mouthwash. Perhaps you can buy it pure.

It takes a long time to degrade chemically, and creates a very unfriendly environment for bacteria and microorganisms.

  • Fluoride is also present in tap water.
    – Chenmunka
    Commented Jun 27, 2017 at 7:50
  • @Chenmunka Yes, at very low levels. Increased levels are OK if it's not drinking water, and in any case it's better that chlorine.
    – user2497
    Commented Jun 27, 2017 at 10:26

add some bleach to it, that should kill the bacteria. they are right though, water shouldn't smell that bad. spray everything with bleach and add it to the water

  • That answer has already been given.
    – Chenmunka
    Commented Jun 27, 2017 at 12:46

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