Repairing a Leaking Exo Terra Aquarium: A Step-by-Step Guide

Updated at: 10/02/2025

Exo Terra terrariums, known for their naturalistic designs, are a popular choice for reptile and amphibian keepers. However, like any glass enclosure, they are susceptible to damage, and a leaking terrarium can quickly become a significant problem, causing water damage, potential harm to your pet, and a stressful cleanup. A cracked or compromised seal can lead to a frustrating and potentially costly repair, but with the right approach, many leaks can be fixed successfully at home.

This guide focuses on effectively repairing a leaking Exo Terra aquarium, walking you through the process from identifying the source of the leak to completing the repair. We will provide a detailed, step-by-step approach that will enable you to assess the damage, gather the necessary materials, and confidently execute the repair, minimizing disruption to your pet's habitat and saving you the expense of replacement. Let's dive into the step-by-step process to get your Exo Terra back in tip-top condition.

Preparation and Safety Guidelines

Tools Needed
  • Exacto knife
  • Flashlight
  • Safety glasses
  • Paper towels
  • S1 Silicone sealant
  • Small dish of water
  • Rubber gloves
Safety Guidelines
  • Always disconnect the aquarium from the power source before starting any repairs. Electrical shock is a serious risk.
  • Wear appropriate safety gear, including gloves and eye protection, to protect yourself from sharp edges, broken glass, and chemicals.
  • If the leak is extensive or you're unsure about the repair, consult a professional aquarium repair service. Attempting a complex repair incorrectly could worsen the damage.

Step-by-Step Instructions

  1. Leak Identification and Preparation

    • Locate and identify the leak. Use a flashlight to carefully examine the silicone sealant for cracks or gaps.
    • Carefully remove the old silicone sealant around the leak using an Exacto knife. Wear safety glasses to protect your eyes from flying glass shards.
    Carefully remove the old silicone sealant around the leak using an Exacto knife. Wear safety glasses to protect your eyes from flying glass shards.Carefully remove the old silicone sealant around the leak using an Exacto knife. Wear safety glasses to protect your eyes from flying glass shards.
    Leak Identification and Preparation

  2. Cleaning and Surface Preparation

    • Thoroughly clean the area to be resealed. Ensure all old silicone is removed. Silicone does not stick to silicone.
    Thoroughly clean the area to be resealed. Ensure all old silicone is removed. Silicone does not stick to silicone.
    Cleaning and Surface Preparation

  3. Silicone Application

    • Apply a generous bead of S1 silicone sealant (aquarium safe, no mold inhibitors) to the cleaned area. Use a wet finger to smooth out the silicone, preventing it from sticking to your finger.
    Apply a generous bead of S1 silicone sealant (aquarium safe, no mold inhibitors) to the cleaned area. Use a wet finger to smooth out the silicone, preventing it from sticking to your finger.
    Silicone Application

  4. Curing

    • Allow the silicone to cure completely (approximately 72 hours).
    Allow the silicone to cure completely (approximately 72 hours).
    Curing

  5. Leak Test

    • Perform a leak test. Fill the tank with water and observe for any leaks. Angle the tank to ensure thorough testing of the repaired area.

Read more: How to Deep Clean Your Leopard Gecko's Tank: A Step-by-Step Guide

Tips

  • Wear safety glasses when removing old silicone to protect your eyes from glass shards.
  • Use S1 silicone sealant, as it is aquarium safe and does not contain mold inhibitors.
  • Use a wet finger to smooth the silicone sealant, preventing it from sticking to your finger and ensuring a smooth, even application.
  • Allow the silicone to cure completely before performing a leak test.

Common Mistakes to Avoid

1. Using the wrong sealant

Reason: Incorrect sealant choice (e.g., silicone not designed for aquariums) can lead to leaks or a sealant that degrades quickly in contact with water, causing future problems.
Solution: Always use a 100% silicone sealant specifically designed for aquariums and terrariums.

2. Insufficient sealant application

Reason: Applying too thin a bead of sealant or not covering the entire seam adequately results in weak points where water can seep through.
Solution: Apply a generous, continuous bead of sealant, ensuring complete coverage of the seam and overlapping slightly onto the surrounding surfaces.

3. Ignoring proper curing time

Reason: Rushing the curing process by filling the tank before the sealant is fully cured will compromise its strength and lead to leaks.
Solution: Allow the sealant to cure completely for the time specified by the manufacturer before adding water or substrate.

FAQs

What kind of sealant should I use to repair my leaking Exo Terra aquarium?
Use a high-quality, silicone sealant specifically designed for aquariums and terrariums. Avoid using general-purpose silicones as they may contain harmful chemicals and may not be waterproof enough for long-term use. Look for one that's non-toxic and safe for reptiles and amphibians.
How long do I need to wait before refilling my Exo Terra aquarium after repairing a leak?
Allow the sealant to cure completely according to the manufacturer's instructions. This usually takes 24-72 hours, but it's best to err on the side of caution and wait longer. Before refilling, thoroughly inspect the repair to ensure there are no gaps or weaknesses in the seal.
Exo Terra terrariums are a popular choice for reptile keepers, offering a robust and aesthetically pleasing environment. However, even the best-made enclosures can suffer from leaks over time. If you've invested in a high-quality terrarium, such as those featured in our previous guide on the top five snake habitats available to reptile enthusiasts, you'll want to address any leaks promptly to protect your reptile and your home. This step-by-step guide will help you repair a leaking Exo Terra aquarium and get your reptile back into a safe and secure environment.