12 Steps Guide: How To Reseal A Fish Tank Effectively

Do you have a leaky home aquarium?

Are water droplets seeping out of the corners and cracks in your tank?

Does the sealant on your tank appear to be drying up or cracking? If so, then there’s a valid reason to panic, but you shouldn’t be.

I’m here to help teach you how to reseal a fish tank easily in your home aquarium. But, before that, let me say why we are so concerned about our aquariums. 

A fish tank is a container of water where fish, other creatures, and plants are live together. Most people keep fish as a part of their hobby, But having an aquarium has plenty of benefits.

These tanks are beautiful to look at when you locate them at a focal point in any room. Nowadays, human lives have turned busy and chaotic such that we require something to help us focus, recharge, and relax. 

Some individuals indicate that viewing this vessel is therapeutic as it reduces stress, lowers blood pressure, and calming effect. Fish tanks also are educational to the kids as they are taught responsibility while caring for the animals.

A healthy fish tank is achieved by maintenance, which includes resealing it when it starts leaking. I’ve been keeping fish for years, and I have had several occasions where I also needed to reseal my home aquarium.

I know that it can be a bit difficult, but I will provide you with some helpful tips to make the process easier. Let’s know how to reseal a fish tank effortlessly.

Reseal an Aquarium with Sealant

It is crucial to keep checking on the container if there is a leakage because a compromised fish tank is a problem for underwater animals.

Test it by grabbing paper towels and running them through the seams. If water is dripping through the seams, your paper towels will get soaked.

If you realize the presence of moisture, you need to repair your tank. While resealing, look for sealants compatible both for saltwater and freshwater; and capable of withstanding water pressure.

Additionally, select an adhesive with non-toxic formulas for the safety of the aquarium. Finally, avoid causing danger to your friends in the fish tank by exposing them to harmful sealants.

Related article: 9 Best Aquarium Silicone – Updated Buying Guide

Why Should I Use Aquarium Sealant?

When the seals are damaged and water has high pressure, your surfaces might flood in no time. For this instance, fish tank sealant is crucial in repairs when water is seeping through the seams.

Resealing is a simple process, but selecting an aquarium-safe sealant (safe for fish and other critters) is vital.

Additionally, this solution has to be a real lifesaver since it can fix significant and minor leaking issues. It provides safety to the inhabitants, whether fish or plants, and protects them from injuries and stress.

Notably, formulas such as aquarium safe silicon, when applied, last for years. Moreover, it is perfect for fish tanks since it can withstand water immersion and is resistant to salt mist and seawater.

Bear in mind that when your tank is large or the glass is cracked, seek a stronger sealant or contact a professional.

How to Choose An Aquarium-Safe Silicone Sealant

Silicon sealant is an elastic gel used in fixing a leaking aquarium. It has excellent adhesion on glass and is resistant to harsh environmental influences and aging.

However, while buying this solution, you need to know if the manufacturers considered safety. Most of the transparent silicone sealants are safe, but you must look at the label. You have to source an aquarium-safe adhesive.

As the name implies, aquarium-safe silicone sealant is a type of silicone sealant used in an aquarium without harming aquatic life.

The question on everyone’s mind when they’re looking for a new adhesive is, “will this glue harm my fish?” You might come across packages that indicate if the formula is harmless for aquariums.

Note that it is crucial to check the tensile strength, which refers to the amount of pressure the silicone can handle. Keep in mind that there are those formulas meant for small seepages while others to seal large leaks.

Consider the curing time since placing it on the water before it is dry can cause the chemicals to dissolve, harming the aquatic life. However, when it is cured, silicone adheres to many surfaces and environments.

What Do You Need to Reseal A Fish Tank

What do you need to reseal a fish tank

Resealing your fish tank requires several things: 

A Stable Surface: It would be best to have a nice stable workspace with a soft working surface; to prevent damage to the glass aquarium while resealing. 

Aquarium-safe Sealant: Notably, purchase a tube of aquarium sealant readily available at the local stores. 

A Knife Or Razor: To cut away the old adhesive, you require a utility knife and a razor scraper. A strong razor and its holder are necessary for ensuring they are unbreakable while removing the gel.

Alcohol Pad: Applying a new sealant requires a clean surface; hence use rubbing alcohol and cloth to ensure that the tank is ready for resealing. 

Vacuum Cleaner: A vacuum is used in getting out dirt and debris, especially when you are resealing the bottom of the aquarium. 

Disposable Gloves: Remember that you must use disposable gloves while repairing the leaking parts to avoid contact with harmful chemicals. 

Other supplies and tools include masking tape, sponge, or paper towels.

How to Reseal A Fish Tank: (Step-By-Step)

Step-1: Remove the Fish Tank

Owning a fish tank brings plenty of responsibilities. In addition to taking care of the animals and other aquatic life, you should keep the tank in good condition. If there is any leaking, reseal the tank.

However, before starting your repairing process, ensure that you have removed the fish and transferred them to a safe place.  Avoid risking their lives by using silicon sealant while they are inside the tank.

Please ensure the alternative tank is suitable for your pet’s survival and comfort. In this instance, a quarantine tank is pretty handy for temporarily shifting fish to a safe place. Please read my article on how to build a quarantine tank

Step1&2- Move fish in a separate tank and drain all water from the tank

Step-2: Completely Drain the Tank

After taking your fish off the aquarium, drain the space. Some people prefer draining the water level until it is below the seam to be fixed.

However, when you want to repair all the seams with leakage, empty the container. Remember that you want to ensure that every part with seepage is repaired once and for all.

Step-3: Clean Your Tank

Before you start the procedure of resealing, ensure you clean your tank. Use a glass cleaner and a sponge to achieve a high level of cleanliness.

Also, you can use paper towels to avoid any mess. Get grime off the glass surface to make it smooth. The glue or sealant does not work well on a dusty and dirty surface.

Step3&4 - Use glass cleaner or sponge to clean the tank & remove old seal with knife or razor

Step-4: Removing Old Sealant

After your fish tank is clean, start removing the existing sealant. Use a utility knife or a razor to pierce through the silicone. Using these tools, scrape the sides of the glass.

Once you complete getting rid of the old gel on one part, continue to the other section until the surface frees off the sealant.

Step-5: Clean The Corners

While you are removing the old sealant on the fish tank, do not forget the corners. If there exists any dirt on the edges, make sure you eliminate it.

Notably, you can use pliers or tweezers to grab any leftover dirt or debris on the aquarium, especially in the hidden parts and corners.

Step5&6 - Clean corners and use a vacuum to remove dirt's

Step-6: Vacuum

After resealing the lowest part of the aquarium, use a vacuum cleaner to ensure it is spotless. Get all the old sealant, dirt, and debris out of place.

Small particles, mostly made of fish waste and dead plants, might get stuck on the spaces of a broken seam, and vacuuming can help remove them.

Step-7: Tape up the Area

Use masking tape to tape up the area you want to reseal. Also, you can start from the bottom and continue till you reach the top part of the fish tank.

Tape the sides of the aquarium by beginning in vertical runs. Notably, you can place it about a quarter inch back from the joints of the container.

Keep in mind that this step ensures the sealant edges will follow a straight line after the procedure.

Step7&8 - Tape up with masking tape and apply sealant on the glass joint

Step-8: Add the Sealant

Once your masking tape is in place, apply a ¼” bead of aquarium sealant on the glass joints. Move to the interior of the fish tank and fill all the gaps with the solution.

Ensure all glass walls are separated with a silicone bead to prevent bubbles from being trapped in the seal.

Do not forget to apply on the inner bead of sealant to reinforce strength and durability.

Step-9: Spread the Sealant

After applying the sealant on the aquarium surface:

  1. Spread it.
  2. Remember that you do not have to use a large amount of the formula, but ensure no exposed gaps or narrow points in the sealant line.
  3. Therefore, use your finger to flatten the freshly applied gel until it gets even.
Step9&10 - Use finger to evenly spread the sealant and Repeat the process until silicone cover each inch of joint

Step-10: Repeat The Process

Redo the procedure of sealant application till the silicone covers each inch of the joint nicely. If there are places on the seam without the formula, smear more of it.

Step-11: Let It Dry

When you complete the process, let it dry for 24 to 48 hours. Avoid refilling the aquarium with water before it has completely dried.

Step11&12 - let the sealant dry for 24 to 48 hours and test the tank, if ok start using the aquarium

Step-12: Test the Tank

To avoid recurring leakage:

  1. Test the tank after the sealant has dried up.
  2. Fill half of the container with water and keep an eye on it for some hours.
  3. Repeat the process of resealing when you realize there is seepage on some parts. 

If everything is well, you can start using the aquarium.  If you like video instructions, check the below video for a better understanding. 

Wrap Up

A fish tank is an excellent way to enhance the décor of your home and give yourself many benefits. However, a leaky aquarium can threaten that impression with just one spill!

For this reason, it’s crucial to follow these guidelines to seal up any leaks promptly before they do lasting damage.

If you have any experience with this repairing job, I will highly appreciate your feedback. Please feel free to comment.

Sujit Modak

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