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No matter how meticulous you are when washing plastic cutlery and containers, hard water will always leave a chalky or film-like residue on the surface of plasticware, making it look old and dirty.
The cloudy residue is what we normally call ‘water spots.’
The calcium and magnesium deposits present in hard water may be safe to consume in small quantities, but it does make food and plastic containers look unhygienic and unappetizing.
If you notice a filmy or cloudy look on your plastic containers and appliances, don’t worry. There are several proven ways to remove stubborn hard water stains from plastic.
Vinegar Rinse

Using vinegar for cleaning is akin to using chlorine bleach, only safer. You would not want to use toxic chemicals to clean plastic containers you use for food, right? This is how you make a safer alternative. White vinegar is terrific in removing hard water stains, as it breaks down bacteria and mineral deposits that are in your plastic.
Step 1: Mix two tablespoons of white vinegar for every cup of water in a large basin
Step 2: Place your hard water-stained containers in the basin and make sure they are completely soaked
Step 3: Leave the plastic containers soaked for at least two hours
Step 4: Dry the containers using clean kitchen cloths or napkins. Do not rinse with hard water as this will defeat the purpose of using a vinegar rinse
Step 5: Air dry containers overnight to completely remove the stench of white vinegar.
Step 6: Repeat as needed once you notice the containers clouding up again.
Bonus Tip: If you need to clean plastic windows, pour some of the water-vinegar solution to a spray bottle and apply it on the surface of your window, then lightly scrub with a soft cloth, doing circular motions with your hand until all the stains have faded.
Lemon/Lime Water Rinse

If you cannot stand the strong smell of white vinegar, there are fruits you can extract juices from, which can also produce the same cleaning effect as white vinegar. In fact, any fruit that’s highly acidic can do the trick, but you will find that lemon and lime actually leave behind a fresh, fragrant smell that sticks to your plastic containers which make them pleasant to use.
Step 1: Completely squeeze out your fruit of choice (make sure it has high acidity)
Step 2: Filter the fruit juice and take out any fruit chunks or pulp. You need a liquid solution for it to work.
Step 3: For light stains, mix equal parts fruit juice and water and transfer solution to a spray bottle. Use this to mist your plastic containers after washing with soap and water. For tougher, years-old water spots, skip the part where you dilute the fruit extract with water. Just directly apply the lemon/lime juice to problematic plastics and let it sit for at least 15 minutes.
Step 4: Use fine, untextured cloth to wipe the lemon or lime solution from your plastic containers and appliances.
Step 5: Let it air dry for at least 6 hours before use if you want the fruity smell to be gone from the containers completely. Of course, you can always opt to use the containers at once after wiping it down, if you enjoy the extra smell of fruit on your food containers.
Baking Soda Paste

Baking soda mixed with water is considered a general stain remover. What many people don’t know is that baking soda is also an effective weapon against water spots. You just have to make sure the paste is less potent than the one used to remove stains from clothes.
Step 1: You need 8 tablespoons of baking soda for every cup of water. Make sure the paste solution is mixed well and doesn’t have any lumps or solid particles. These solid particles may leave unwanted traces and scratches on your transparent plastic containers.
Step 2: Apply the baking soda paste onto a fine cloth or onto washing gloves.
Step 3: Manually wipe the cloth all over the plastic containers or windows, as if you’re washing with dishwashing liquid.
Step 4: Use mineral or filtered water when rinsing the baking soda paste off of your plastic. Unlike the vinegar and fruit-based solutions, you cannot simply air-dry containers that’s been cleaned with baking soda, since you don’t really want to risk ingesting contaminated baking soda. However, rinsing with hard water would simply deposit minerals onto your plastic surfaces again, making the whole baking soda exercise pointless.
Limescale Remover
Alternatively, you can also use commercially available limescale (hardness minerals) removers. These solutions have been tested to digest enzymes and break down unwanted chemicals on surfaces. Make sure you follow the directions or instructions provided along with your chosen limescale remover.
Soften your water
If you want a more permanent solution to the effect of hard water on plastics, you would have to take steps to soften the water that you use when washing plastic dishes and containers.
There are two ways to do this.
1- Water Filtration System
If you opt for a whole-house water filtration system, you can remove contaminants from the water and ensure that it’s clean and safe to use. However, while some water filtration systems can soften water to an extent, they don’t completely remove hardness ions. For this, you would have to get a water softening system.
2- Water Softening System
As the name implies, these devices make sure your water is softened by removing all hardness minerals using a process known as ion exchange. The system takes out calcium and magnesium, replacing them with sodium ions.
This will drastically improve your water and mitigate the negative effects of hard water on your plastic containers, glassware, appliances, hair and skin, to name a few. However, it will not remove any other contaminants in your water and will not filter it.
Bottom Line
Hard water is hard on plastic containers and appliances, adding a filmy residue, spots and stains that can make it look unwashed. While this is safe and not something to worry about, it is unpleasant and ugly to look at.
Luckily, there are many ways to solve this problem, from temporary fixes like rinses and washes and more permanent solutions like installing a water softening system. We recommend opting for a water softening system, but they’re not for everyone as they come with a fair amount of initial cost, maintenance and ongoing cost. If you want to learn more about softening hard water, check our detailed article here.