Customizing the look of an aquarium tank is very popular these days and with the spike in the popularity of aquascaping continuing to climb, the number of people wanting to most unique, custom looking tank is constantly increasing.
We have seen a number of questions about using various types of decorations in a fish tank recently but one thing that is becoming more and more common is using polymer clay to make your own, custom tank decorations.
Each month, we see a number of people reaching out and asking questions about if polymer clay is aquarium safe or not and just like with most things, it’s going to depend on a number of different things.
Although polymer clay can be inert and safe to use in your aquarium in some situations, it can cause problems when not cured correctly or if it is damaged so we wanted to publish our own article going over using polymer clay in your tanks.
What Is Polymer Clay?
Polymer clay is a type of oven-bake modeling clay that can be used for a wide variety of different art and craft projects.
The main thing that sets polymer clay apart from other types of oven-bake clays is that it is made from polymers, which are long chains of molecules that give the clay its unique properties.
When it comes to using polymer clay in your aquarium, there are two main things that you need to take into consideration;
How the clay is cured and; if the clay is damaged.
We will go into more detail about each of these factors below but if you are thinking about using polymer clay in your aquarium, we would recommend that you err on the side of caution and place any polymer clay decorations in a test body of water for a week the check the water parameters prior to adding it to your primary tank.
Is Polymer Clay Safe For A Fish Tank?
As we touched on above, whether or not polymer clay is safe for your fish tank is going to depend on a couple of different factors; how the clay is cured and if the clay is damaged.
If the clay is cured correctly, it should be safe to use in your aquarium however, if the clay is not cured correctly or if it is damaged, it can leach toxins into the water which can be harmful to your fish.
When it comes to curing the clay, we would always recommend that you follow the manufacturer’s instructions to ensure that the clay is cured correctly.
In most cases, curing the clay correctly will involve baking it in an oven at a specific temperature for a set period of time however, some clays may require that you cure them in a different way so it is important that you check the manufacturer’s instructions.
Once the clay is cured, it should be safe to use in your aquarium however, if the clay is damaged in any way, it can leach toxins into the water which can be harmful to your fish.
How Is Polymer Clay Cured?
Polymer clay is cured by baking it in an oven at a specific temperature for a certain amount of time.
The type of clay that you use, as well as the brand, will determine the exact curing temperature and time but in most cases, you will need to bake the clay at a temperature of between 265 and 275 degrees Fahrenheit for 15 to 30 minutes.
Once the clay is cured, it will be hard and brittle and will no longer be pliable.
Can Polymer Clay Be Submerged In Water?
Polymer clay can be submerged in water however, it is important to note that the clay will absorb water over time and will eventually break down.
For this reason, we would always recommend that you place any polymer clay decorations in a test body of water for a week prior to adding them to your primary tank so you are confident that the clay has been cured correctly.
This will give you a chance to see how the clay reacts to being submerged in water and will also allow you to check the water parameters prior to adding it to your main tank.
Just because polymer clay will eventually break down does not mean that it will be causing problems in your tank for many years due to how long modern polymer clay formulas are actually able to last.
Alternatives To Polymer Clay For Your Aquarium!
While polymer clay is a great material for crafting, it is not necessarily the best material to use in your aquarium.
This is because, as we touched on above, polymer clay can leach toxins into the water if it is not cured correctly or if it becomes damaged.
For this reason, we would always recommend that you use an alternative material such as glass, ceramic, or resin when crafting decorations for your aquarium.
Not only are these materials non-toxic, but they are also much more durable and will not break down over time like polymer clay can.
Is counter point to using these materials is that they usually need specialist equipment where as polymer clay is very beginner friendly and easy to use so there is always a trade off.