Can mold grow in water? Interesting question. We all know that mold needs water or another moisture source to grow but can it actually grow in water itself?
A lot of people would assume that yes it can. Why? Because if you have ever owned a reusable water bottle, you likely have had to clean mold in the water bottle. But was it the water itself that grew mold or something else?
What about white water mold? Swimming pool mold? Mold in water pipes? Is that actually mold growing in water?
Today I am going to tackle the subject of water mold as well as how to test for mold in water. Let’s get started shall we?
- Can Water Grow Mold?
- How Does Mold Get Into My Water Supply?
- How Does Mold Grow In Water Pipes?
- Signs You Have Mold In Water Pipes
- How To Remove Mold In Water Pipes
- Speaking Of Wastewater Pipes
- Can Mold In Water Make You Sick?
- How Can You Prevent Mold In Your Water?
- What Is White Water Mold?
- What About Water Bottle Mold?
- How To Test For Mold In Water
Can Water Grow Mold?
Mold can grow in water if the water is rich in nutrients. The mold will form a mat on the surface of the water and produce spores. If the water contains little or no nutrients, then the initial growth would die for lack of nutrients.
Water can only grow mold when it is at rest. Moving water can carry spores but it cannot “grow” mold while in motion. A pond with little movement is more likely to grow water than a river which is constantly in motion. Water in a well or at a water treatment plant is more likely to grow mold since it can remain stagnant for a while.
How Does Mold Get Into My Water Supply?
- If your water source comes from a well, then you might be at risk for mold in your water if your well cap is damaged or is not adequately sealed.
- If your system has high levels of oxygen and an organic food source (this could be something as simple as a paper filter cartridge), mold has the ability to survive in your water.
- You may have mold growth in your water softener, water purifier, or water storage tank.
- Your faucet aerator (the screen assembly) might have mold growth.
How Does Mold Grow In Water Pipes?
It is rather difficult for mold to grow in water pipes. Water pipes don’t have adequate oxygen or food for mold to grow significantly, but they do have a moist, dark environment that allows mold to form under the right circumstances.
Mineral build up in your pipes would provide a food source. A tree root that infiltrates your pipes can provide food for mold. If you have tiny holes in your pipes (copper pipes are especially prone to developing microscopic holes) then dirt and other particles can get inside your water pipes allowing mold to grow.
Signs You Have Mold In Water Pipes
- If you inspect inside an accessible water pipe and see mold, then your entire water line might have a mold problem. Don’t confuse calcium build up with mold. Calcium build up is hard and doesn’t easily come off if you rub it with your finger. Mold will rub right onto your finger.
- You smell a moldy or musty smell when you run your water.
- You notice a gritty, dirt like substance at the bottom and sides of your toilet.
- You see an abnormal amount of mold in your shower, bathtub or toilet AND it grows back very quickly after removal.
- Mold is growing in other locations around your home.
How To Remove Mold In Water Pipes
This is a bit tricky and in my personal experience there is no hard and firm, 100% guaranteed way to accomplish this short of replacing your entire plumbing system. Unlike wastewater pipes which can be cleaned, water pipes are much more difficult to flush.
You basically need to tackle any mold in your water pipes by pouring a cleaning solution into your main water supply line and then flushing your cold water lines. I would just use vinegar myself but there are some commercial products available. They are all a little too chemical based for my personal comfort.
How to flush the cold water lines
- Turn the cold water faucet for your kitchen sink on all the way and let the water run for one to two minutes to flush cold water through the pipes.
- Test the water to be sure it is very cold. This is one way to know the water you are now getting through the faucet has not been sitting in your home’s pipes.
- Turn on the other cold water faucets one by one, each for one to two minutes, to flush cold water through the remaining pipes. Make sure to flush the outside spigot, refrigerator (if yours is connected to water), and washing machine.
- You can now use your water as you normally would.
Don’t Forget About Your Water Heater!
If you have mold in your water or water pipes then you need to get it out of your water heater. Again, there isn’t some simple and full proof way of doing this. However, there are two options.
The first is to basically drain all the water out of your water heater. You do this by turning on every HOT WATER faucet in your home. Run the water for 15 minutes for a 40-gallon tank or 30 minutes for an 80-gallon tank. Your water heater tank should be completely empty. Allow it to refill. This may or may not solve the problem and is best used for a very minor water mold issue.
For a more serious water mold issue, I would follow the instructions on how to clean your hot water tank with vinegar here.
Speaking Of Wastewater Pipes
It is actually a VERY good idea to clean these once a month. Wastewater lines are VERY likely to develop a mold problem seeing that things like food, hair, soap, scum, and other debris regularly make their way down there.
You need to do this in every sink, shower, and bathtub simultaneously. If it has a drain, do it.
- Pour ½ cup of properly diluted EC3 Mold Solution down each drain. Allow it to sit for one hour.
- Boil two cups of water and pour down the drain, then run the hot water from the tap for several minutes.
- Pour a quarter-cup of baking soda into the drain.
- Pour one cup of vinegar into the drain and allow it to sit for 30 minutes. This will fizz up which helps to loosen any mold growth inside the pipes.
- Boil two more cups of water and pour into the drain, then run the hot water for several minutes.
- Repeat monthly
Important to note! NEVER pour bleach into your plumbing system. It is very abrasive to all pipes.
Can Mold In Water Make You Sick?
Yes it can. Drinking mold or bathing in mold is not doing anyone any favors. Everyone will react differently but there is a 99% change that the mold in your water is causing some sort of health related issue be is mild or more severe.
How Can You Prevent Mold In Your Water?
The number one way to prevent mold in your water is to install a top of the line whole house water purification system that has a demonstrated track record of removing fungal contaminates.
I have tried quite a few systems which failed at this. However, after years of hunting, I finally found a whole house water purifier that will keep unwanted mold spores (along with everything else) out of your water supply. It doesn’t use salt, chlorine, or any other chemical. It truly is the best whole house water purification system on the market. I am not affiliated with this product nor do I have a direct link to where you can purchase it. Here is a PDF you can download that tells you more about the Watchman. You can then contact your trusted plumber to purchase and install this system for you.
Other ways to prevent mold in your water include:
- Clean the faucet aerators weekly and replace yearly.
- Practice good overall mold prevention around the house as well as outdoors. The 27 tips to prevent mold are a great place to start.
- If you suspect mold in your home, test for it to see exactly what you might be dealing with.
What Is White Water Mold?
White water mold is a mucous-like substance that looks like shredded tissue paper when floating in the water. The color may range from white to shades of pink, violet, yellow or gray tones. It is not the same thing as algae although it is an organic substance.
White water mold forms a heavy, protective coating, providing the organism with an uncommonly high level of protection that is very resilient against both halogen-based (chlorine, bromine) and non-halogen sanitizers and germicides. This means that even if you destroy the white water mold, it can come back rather quickly since it is so resilient.
White water mold can be found on pool ladders, toys, floats, steps, automatic pool cleaner parts, fountains, directional fittings, skimmer baskets, weirs, and garden hoses, etc. Even tiny quantities of it can cause the problem to reoccur. It is usually caused by improper water and pool maintenance, environment and poor circulation. Basically, it is an overgrowth of naturally occurring Biofilms lying on pool surfaces and hiding in spots that are less accessible.
How you remove white water mold depends on your pool or hot tub. Speak with your local pool professional to determine your best course of action.
The best way to avoid white water mold is through good pool maintenance. Don’t slack in this department.
What About Water Bottle Mold?
Water bottle mold is a huge issue. 90% of the time it occurs because of improper water bottle hygiene. AKA – you didn’t thoroughly wash your reusable water bottle at the end of the day. You absolutely have to wash every square inch of it, especially if it has a flip top to drink from. (The other 10% of the time it is because you have mold in your water supply).
Biofilms and other materials from our mouths cling to our reusable water bottle like a dung beetle clings to, well dung. You have a nice wet, dark environment with food for mold to flourish in.
Jason Tetro, microbiologist and author of The Germ Files shares some great information about water bottle mold.
It takes a few days, most likely—unless it’s sugar water, at which point it’ll grow within 48 hours. Usually it’s over the course of five days, which is usually how often people wash their water bottles. At that point there’s as very good likelihood you’ll have some kind of growth. One method of growth is on surfaces. The inner surface of a water bottle can essentially harbor biofilms, and these will allow numerous different species—including bacteria and fungi—to grow, and they’ll be able to stick there because biofilms are very sticky. So even rinsing and shaking your water bottle may not be enough.”
Then Tetro mentions “floaties,” a term he coined for the mold that floats on the top of the water’s surface.
These are the bacteria and fungi in the water itself. This is more rare, because you need to have a high level of food in there.”
Tetro also shares the best way to prevent mold growth in your water bottle.
You’re going to have to clean it manually. Use a brush, some soap, and hot water. If water is over about 160 degrees Fahrenheit, the bacteria and fungi won’t grow—they die. So the best thing for you to do is boil water and put it directly into your water bottle and fill it straight up to the top. Add a little vinegar if you want because as an acid it helps to break up some of the stuff. Then let it sit for about three minutes. That’ll pretty much kill everything. And if you’ve gotten rid of the biofilms with a brush and on the lip with a towel, you’re pretty much going to have a clean water bottle.”
If you have a bottle with a very small mouth opening, he advises to use your fingers to get underneath the lip.
How To Test For Mold In Water
There are a few options when it comes to how to test for mold in water. Testing for mold in water is actually pretty easy. If you have children, you can turn this into a science experience. Let’s look at the first method.
How To Test For Mold In Water With Petri Dishes
- Purchase these petri dish style plates. Do not substitute with another type of test plate.
- Open the test plate.
- Use a clean eye dropper or pipette like this to transfer about 10 drops of water (taken directly from a running stream of water from your faucet) onto the surface.
- Replace the lid, tape it shut and wrap it in foil.
- Place the test plate in a location that stays room temperature. Do not move the sample for 5 days.
- After 5 days gently lift the foil and check the plate for growth. If there is none leave it an additional 2 days for a total of 7 days.
- If after 7 days there is no growth then there is no mold in your water. If there is growth, repeat the test with a new test plate to either confirm the original results or rebuke them.
There are some HUGE limitations to this water mold testing method. First, cross contamination is a big risk. Second, you might get mold growth but you won’t know what types of mold are in your water. This could make a difference in how you go about dealing with the situation. Third, there are a lot of false positives. It is a great way to rule water mold IN but not the ideal way to rule water mold OUT.
My Preferred Way To Test For Mold In Water
If it were me, I would use the Tap Score Mold and Fungus Water Test.
It is very affordable and very accurate. Tap Score’s Total Mold Test will analyze your water quality for mold and fungal contamination. This popular water quality mold test includes species like black mold, (Asp. spp.) and other Aspergillus formations with full speciation of the Penicillium & Cladosporium genus. Results will be reported as a quantitative fungal analysis, measuring your detected species in units of colony forming units per mL (CFU / mL).
Tap Score also has all kinds of other great water tests. You can test for Glyphosate, Radon, Plastics and Microplastics, and so much more! You can even test your favorite bottled water! Check out all their tests here.