Your aquarium is made possible because of the glass tank that holds a body of water, providing a safe habitat for your aquatic buddies.
However, as with any aspect of your aquarium, the tank itself can malfunction and spring a leak – a leak left unattended can prove to be deadly to your fish.
Therefore, it is important to always look out for leaks and know how to fix leaking aquarium.
In this post, we’ll look at a specific question: can you seal an aquarium from the outside?
We’ll look at the answer and also look at how to seal a fish tank properly.
Let’s get started.
What is Aquarium Seal and Why is it Used
If you don’t know this already, a fish tank is made up of panes of glass held together by glue; this means that the seams are the weakest parts.
So, when you get a leak somehow, it is probably at the seams; the good news is there is a way to seal fish tank, although it is a somewhat arduous process.
You have a silicone seal both on the insides and outside of the tank, both performing the same function of making sure the water stays in the tank.
If we go a little bit deeper, there’s another type of seal: the one that is actually between the panes of glass.
This is a high-quality seal used during the manufacture of the tank; it is a tough form of seal that is responsible for the structural integrity of the tank – replacing this by yourself is next to impossible as you will have to disassemble the whole thing.
So, while the seal between the panes is primarily meant to take the load and hold the structure together, the seal surrounding it makes the seam waterproof.
When we talk about sealing an aquarium, we’re usually talking about the seal that surrounds the seams.
Can You Seal An Aquarium From The Outside
There are a couple of good reasons why you would want to seal fish tank from the outside.
First off, sealing aquarium from the outside means you do not have to empty the tank of its contents; this will save you a lot of trouble as you don’t have to transfer your fish somewhere, drain the water, or remove gravel, plants, equipment, etc.
Secondly, resealing an aquarium from the outside is much easier than doing it on the inside – you will be constrained by the tank itself when sealing the insides.
So, can you seal an aquarium from the outside? Short answer is yes, but is it really recommended? I don’t think so.
Earlier we talked about the seals on the inside as well as the outside; it stands to reason that both are necessary to make sure water doesn’t leak from the tank.
In fact, as it turns out, the seal on the inside is more important than the one outside; it is really not a surprise when you consider that the inside seal is in contact with the water. It does a crucial job of withstanding the water pressure and making the tank structurally stronger.
Just one seal would not be able to withstand the immense water pressure.
Moreover, aquarium seal does not bond well with wet surfaces, so if your tank is full of water, the constant leaking can interfere with the resealing process.
Further complicating matters, new seal does not bond with the old one, so you will have to remove the old one before resealing aquarium. It is hard to do that when the tank is full of water.
You are in some luck if the leak is at the top part of the tank, as you can drain the water just below this level and don’t have to evacuate your whole tank.
Lastly, resealing a fish tank is only done to stop the seams from leaking, not to seal cracked glass.
Which Aquarium Seal Should You Use
The choice of aquarium seal is important, as you want something that can do the job while not posing any harm to your fish.
The question is, can you use regular silicone to seal a fish tank?
Well, 100% pure silicone is safe for fish. It is a durable material that can last even a decade and is waterproof. Moreover, it is a flexible material, meaning it can withstand high loads without breaking.
The problem arises with the various additives added to silicone that can harm your fish – the “regular” silicone you buy at the hardware store may come with these harmful additives.
Just to be sure, you can get a dedicated aquarium silicone sealant that is completely safe for fish. You can buy aquarium safe sealer HERE
How To Reseal An Aquarium
Follow these easy steps when resealing aquarium.
Step 1: Identify the Leak
Find out exactly where the leak is coming from; you can reseal just this part instead of resealing the whole tank.
You can perform an aquarium leak test to figure out where the water is leaking from.
Step 2: Remove the Old Silicone
As we said earlier, new silicone does not bond with the existing one, so you will have to remove it completely from where you want to reseal the tank.
Use a sharp razor to separate the silicone from the glass. Make sure you don’t cut the sealant between the panes (or yourself).
Remove as much existing silicone as you can, before moving to step 2.
Step 3: Clean the Residue
No matter how well you cut it, there will be some residue left behind.
You can clean the silicone residue with rubbing alcohol or acetone.
Step 4: Apply the Silicone
After making sure you have a sufficient amount of aquarium silicone sealant, apply a quarter-inch bead along the entire length of the seam you would like to fix.
It must be a continuous application because silicone after drying will not bond that well with new silicone.
Wet your finger with water and use it to evenly spread the applied bead of silicone.
If done properly, there shouldn’t be any air bubbles inside the silicone.
After finishing, let it cure for 24-48 hours before you add water to the tank.
Conclusion
It is possible to reseal a leaking aquarium. Although you can indeed seal a fish tank from the outside, it is better to seal both the inside and outside.
A word of warning though: resealing aquarium is a meticulous process – only do it if you know what you are doing.
If your aquarium has sprung a leak and you don’t want to go through the trouble of resealing it, why not consider buying a new aquarium?
It is important to make sure your aquarium is a safe haven for fish – that means making sure there will be no leaks.
Thanks for reading.
