How to Fix a Leaking Aquarium without Draining?

An aquarium is definitely a beautiful addition to the interior of any home. They don’t take up much space and instantly add color and life to a room.

In addition to looking aesthetically pleasing, aquariums also bring a variety of other benefits to your home.

This is why aquariums remain to be highly popular all around the world.

However, before you decide to bring an aquarium into your home, you should know it’s not all fun and games.

Maintaining aquariums is not as easy as it seems.

Cleaning aquariums and ensuring that the water in them is safe for both the fish and plants can take a lot of time and effort on your part.

Since aquariums are made of glass, they also tend to be quite fragile and prone to leaks.

Therefore, if you want to keep an aquarium in your home for a longer period of time, you must first learn how to fix a leaking aquarium.

We’re here today to help you learn exactly that!

Why Do Aquariums Leak?

Aquariums don’t frequently leak due to visibly clear cracks on their glass panes. Instead, an aquarium usually leaks when the sealant in it starts to get worn out.

The sealant is the layer of black substance that is responsible for keeping the glass panes of your aquarium glued together to create the shape of the tank.

This sealant in your aquarium can turn bad or become worn out over time.

As a result, your fish tank slowly starts to leak water without any noticeable cracks on it.

How to Know If Your Aquarium is Leaking

In order to determine if your aquarium is leaking, you must carefully examine the level of water in it.

You can do this by accurately marking the level of water on one day and then checking if it remains unchanged the next day.

If there is a leak in your aquarium then the level of water the next day will obviously be below the initial mark.

How to Spot a Leak in Your Aquarium

A common trick to finding the leaking spot in your aquarium is to wrap a paper towel around it.

The paper towel will get wet on the spot where the water leaks from.

This way you will quickly and easily find out the exact place where the sealant is worn out and causing a leak.

Furthermore, another useful trick to spot the leak in your aquarium is to notice where the level of water became constant.

Your aquarium will continue to leak when the water level is above the leaking spot.

However, it will instantly stop leaking once the water level is below the leaking spot.

This way, you will be able to spot the leak as it has to be right above the constant level of water.

How to Fix a Leaking Aquarium without Draining

Now that we know how to discover a leaking spot in an aquarium, let’s learn how to fix the leak as well.

To make things simpler for you, we will explain how to fix a leaking aquarium without draining in a step-by-step manner below.

Step 1: Remove Some Water

In order to successfully fix a leak in your aquarium, you have to make sure the leaking spot is no longer submerged in the water of the tank.

The spot must be well above the water level so that you can work on it easily.

For this reason, you must use a bucket or a mug to remove some water from the fish tank. The reduced level of water in the aquarium will give you clear access to work on the leaking spot.

You do not have to drain the tank completely to make it empty.

If the leaking spot is positioned really low in your aquarium, then you will have to do some extra work.

Before you can begin removing the water in this case, you should find a temporary holding tank for your fish. The temporary holding tank will be a safe place with plenty of water for your fish to stay in.

This will give you the chance to focus on repairing the leak without worrying about disturbing the fish.

Step 2: Scrape off the Old Sealant

As explained earlier, a worn-out sealant is what causes a leak in an aquarium.

This is why to fix the leaking problem, you must first scrape off the old sealant from your aquarium’s glass surface.

The best tool you can use to easily scrape away the sealant from the glass is a razor blade scraper.

It won’t be so sharp that it will scratch the surface of the glass but will just be sharp enough to remove the worn-out sealant.

Keep in mind that it is imperative for you to remove all of the old sealants inside the tank.

This is because old sealants and new sealants do not stick together.

Therefore, in order for the new sealant to stick well to fix the leak, the old sealant must be properly removed.

Step 3: Clean the Leaking Spot Thoroughly

The next thing to do after scraping off the old sealant is to clean the leaking spot thoroughly.

Once the leaking spot is properly clean, the new silicon will stick to it better to fix the leak.

You can apply some acetone to a damp cloth and rub the leaking spot with it.

This will help remove any residue of the old sealant and also remove the dirt on the glass to make it squeaky clean.

Step 4: Seal the Leaking Spot

After you have cleaned the leaking spot that has to be sealed, it is finally ready for a new sealant.

The sealant you must buy for this job has to be 100% silicon and completely non-toxic silicon.

Also, try to make sure the silicon does not have any fungicides in it.

If you use toxic silicon to seal the leaking spot you will just end up poisoning the water and fish in your aquarium.

If you were thinking of applying a toxic silicon sealant to the outside surface of your aquarium then please don’t go ahead with this.

Fixing the leak from the inside is always more effective.

You should use a caulking gun to apply the silicone sealant on the leaking spot. After that, you can use a caulking tool to smoothen out the silicon into a flat layer.

Make sure to only apply enough amount of silicon to cover the leaking area.

The last thing you want to see is the fish in your aquarium nibbling on the sealant that is sticking out of the glass.

Step 5: Give the New Sealant Enough Time to Dry

All you must do now is be patient and give the new sealant enough time to dry.

As a general rule of thumb remember that silicon takes roughly 24 hours to fully dry up.

We suggest you let the silicone sealant dry for about 48 hours just to be sure it is completely dry. You can also put a heat lamp nearby to expedite the drying process.

If you do not let the new sealant dry properly then it won’t be effective in sealing the leak.

Putting water back into your aquarium right away will only ruin the seal. The silicon will instantly become soft on exposure to water and start to peel off. As a result, all the effort you have made till now will be for nothing.

Step 6: Fill your Aquarium with Water to Check for Leaks

The last and final step of this process is to fill your fish tank up with water and see if it leaks.

Remember to fill the tank slowly once the water level rises above the initial leaking spot.

Fill the tank with water gradually to make sure you don’t add excessive water pressure on the spot suddenly.

If you observe no water leaking from your aquarium after a few hours then congratulations, you have done the job!

Last Few Words

We hope you find the steps in this article easy to do at home on your own. As you can see, knowing how to fix a leaking aquarium is not rocket science.

Instead, fixing a leak is a fairly trouble-free process and can be done at home if you put your mind to it.

All you need to do is buy the right tools for the job and follow the simple instructions given below.

In case your aquarium is still leaking after this carrying out this process, please don’t feel discouraged.

Give yourself credit for at least trying to fix the leak on your own. You can always buy a new tank to replace this one if the problem doesn’t get fixed!

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