Can You Put CLR in a Toilet Tank?

All of us try to clean and make the bathroom hygienic and fresh but overlook the cleaning of the toilet tank, which can cause smell, rust, and dysfunction.

Can You Put CLR in a Toilet Tank? You can put CLR in a toilet tank to remove calcium and mineral buildup, get rid of rust and corrosion, and clean the mold and mildew. It is powerful, eco-friendly, affordable and enhances the durability of the toilet.

Calcium, Lime, and Rust Remover, also known as CLR, is an excellent cleaning product used to clean toilet tanks, bowls, and other household items.

Why would you use CLR in a toilet tank?

It can clean different types of stains, such as stains due to hard water and rust, which look untidy and affect the function of the fixture.

Calcium and mineral buildup

The stagnant hard water in the tank contains a high amount of calcium, lime, magnesium, and other minerals that cause stains and yellow color layers around it.

In addition, it can leave the residual that causes mineral buildup on its interior over time, and it becomes difficult to remove them if you ignore this problem.

Calcium gets harder with time and forms solid deposits of calcium carbonate, especially if it is not used frequently, such as in a guest room or under-stairs bathroom.

CLR includes weak acids, such as glycolic acid, lactic acid, citric acid, sulfamic acid, and gluconic acid, that work efficiently to dissolve the mineral buildup inside the tank and remove the stains.

Most American households have hard water, which causes the problem of limescale in the jet holes that can clog it and affect the performance of the fixture. 

Rust removal

The tank is supposed to be refilled with water about one to a half inches below the tank tub in 10-11 seconds after you flush it down.

There are chances of rust on the pipes and other components inside it because water is always standing and often running through them.

It can cause severe discoloration on the fixture, and rust particles and brown color water into the flushing water.

In addition, the corrosive nature of rust can cause pipe leakage, damage to the flushing lever and valve, and inefficient performance.

It can dissolve rust and iron particles as it has many acids and other chemicals that can avoid the risk of rust and corrosion in the pipes and enhance performance.

Powerful and eco-friendly

It has become famous due to its powerful and efficient cleaning capabilities. However, many people are concerned about using chemical cleaners that might be harmful to use or can fade the original color of the fixture, especially when it comes to the bathroom.

It is an eco-friendly product that does not use any harmful chemicals which can affect you or your toilet if used with proper instructions.

It does not include phosphates, ammonia, or any bleach in its formation, which are the three main pollutants in cleaning products.

It has an award of safer choice from the Environment Protection Agency for a safe and eco-friendly cleaning product to use in the bathroom.

However, it is not 100% eco-friendly because of the weak acidic chemicals but is safe for you and the environment. 

Mold and Mildew

The standing water in it can develop mold and mildew around the corners and tank walls.

It seems untidy and unhygienic as different types of molds that grow in moist and dark places accumulate there. Toilet tanks provide a perfect source of mold and mildew to thrive in hard water with a food source.

The toilet used less frequently has more chance of getting mold and mildew development than the one used more often in a day because of the stagnant water.

Black mold can grow in the water pipes of the tank due to rust and moisture.

CLR plays a significant role in removing mold from it and cleaning the pipes and other components inside them.


The product is affordable such as you can select it in the range of $35 to $65$, depending on the bottle size.

However, it is better to take care of the bathroom fixtures and clean them with effective cleaners to maintain their performance instead of spending money on a new toilet.

You can use CLR for cleaning, and the efficient performance of the tank components will enhance its durability.

You can use one bottle of this product 2-3 times to clean your tank if you select a large-size bottle. It can make the toilet and bowl look new and clean within your budget.

How to use CLR in a toilet tank?

Different acids, water, and surfactants make it safe and powerful to use in the bathroom for cleaning hard stains and rust.

You can start cleaning by using a sponge, scrub brush, CLR, and gloves. Wear gloves and remove the tank lid to see the rust and mineral buildup conditions inside it.

Flush down the water to empty the tank and shut the valve located near the toilet. You can take a scrubbing brush to remove the accumulated dirt around its walls and at the base.

You can apply this on the bottom and sides of the tank carefully to avoid any contact with the metal. Leave it for approximately 2-3 minutes so that the acids inside the product can soak and dissolve the rust and stains.

Take a long, narrow, and medium size scrub brush and rub t all over the bottom, corners, and walls to remove the buildup of lime and calcium.

You can use a sponge and warm water to clean all the components separately, such as the ball float and flapper. Turn on the valve and fill it with water again.

You can flush it 2-3 times to clean it and see if all the components are working correctly. It will look clean and new, and you can use it as usual for daily business.

Things to consider while using CLR in the toilet tank

It is a safe product to use in the bathroom, but it needs some tips and precautions for cleaning.

It is better to use gloves, masks, protective gear, and goggles to avoid damage to your skin or clothes.

Try to test it on a small hidden area before applying it to the bathroom fixture to prevent any risk.

Keep it away from the children, and do not allow your kids to enter the bathroom when you are doing this task. It is necessary for the kid’s safety as they can get the fumes of the chemicals and the foul odor.

Do not leave CLR for more than 2-3 minutes because the acids can affect the porcelain if left for a longer duration.

I recommend you clean the toilet tanks once or twice a year to maintain the performance of all the components and avoid annoying smells.

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