Skip to Content

How To Use Styrofoam In An Aquarium!

The popularity of styrofoam for 3D aquascape backgrounds and aquarium bases in fish tanks is becoming more and more popular.

After a number of popular YouTubers released videos of their latest tanks integrating styrofoam into their setup, we have noticed a spike in the number of people reaching out and asking about using styrofoam in their own tanks.

Due to seeing so many people reaching out about using styrofoam in their aquarium we have decided to publish this dedicated article to try and help as many of our readers as possible.

With more and more content on social media going viral showing how great styrofoam 3D aquascapes can look in aquariums, we feel that the number of people reaching out about using styrofoam in their aquariums is only going to be increasing over the coming years too.

As we see a number of different people asking different questions about integrating styrofoam in their aquarium, we have decided to add a table of contents below.

Our hope is that it will be able to help our readers better integrate their styrofoam into their tank and make it a main feature of their tank or ensure that they are able to correctly use it as a base layer and avoid some of the more common problems that we see.

Is Styrofoam Safe for Aquariums?

Styrofoam is an inert material commonly used for food and drink containers for humans and is generally considered safe for use in aquariums.

Although styrofoam does technically have a half life where it will start to degrade, is it estimated to be around 500 years so adding styrofoam to your aquarium should not cause any problems with many people in the fish keeping community adding styrofoam to their tanks without issue.

Although styrofoam does not actually have any safety issues specific to the styrofoam, a common problem that we so see time and time again is that people will add it to their aquarium in an unsafe way and end up with problems.

For example, using a regular glue rather than an aquarium safe glue and as we covered in our article on aquarium safe glue for rocks, the majority of glue products on the market are not safe and will release toxins into your tank with styrofoam usually getting the blame when it is actually the glue.

Another very common mistake with using styrofoam in aquariums is that people will either not use enough glue or use the wrong type of glue.

If you are using the styrofoam as a 3D design for an aquascape or a base for your tank, this can cause the styrofoam to come away from the glass and start to float causing problems for everything else.

This is why we usually recommend that you actually lock your styrofoam in place by placing rocks on top of it if possible as it will keep your styrofoam in place and not peel away from the glass like glue might.

Does Styrofoam Disintegrate in Aquarium

Styrofoam will technically start to disintegrate after around 500 years it being in your aquarium so it is generally considered safe for use in your tank due to it being an inert material.

Provided you mount the styrofoam in your aquarium correctly, you should have no problems with using it as a part of your setup and you should also be to use it for many years without issue.

It is also very rare that fish will pick at the styrofoam in your tank too so it helps to keep it in tact and in the design that you originally added the styrofoam to your tank.

This is a great benefit of using styrofoam for your aquascapes as some other popular materials will be picked at by fish causing it to quickly lose the shape that you added it to your tank in.

If you are just using the styrofoam as a base layer under your substrate then the substrate will usually prevent your fish from being able to get to it anyway.

If you are thinking of using styrofoam as a base layer under your substrate then please note that you should not rely on the weight of your styrofoam to keep the styrofoam in place in your tank, it will need an aquarium safe glue or rocks to keep the styrofoam in place.

How to Place Styrofoam in An Aquarium

There are a number of different ways that you are able to place styrofoam into an aquarium with aquarium safe glue, rocks, and clips usually being the most common methods to keep styrofoam in place.

There are a number of other methods that you are able to use too but they do tend to present more risk with the main three being the safest.

If you are using the styrofoam in your aquarium as a base layer under your substrate then we would usually recommend that you put the styrofoam in place with some aquarium safe glue and then add your substrate over the styrofoam once the glue has dried.

Depending on the size of your tank, it may also be a good idea to add a few rocks on top of your substrate too as it will secure the styrofoam in place.

If you are wanting to use your styrofoam as a part of an aquascape then there are a large number of different ways that you are able to add the styrofoam to your aquarium.

Most of the time, you will shape the styrofoam as you need it, place it in your tank, glue it in place or use physical clips to secure it, and then add the water, plans, and fish to the tank once the styrofoam is secure.


That brings our article going over using styrofoam in an aquarium to an end. We hope that we have been able to help you better understand the various ways that you are able to integrate the styrofoam into your tank as well as how you are able to safely secure it in place too. The main mistake that we see people make time and time again when adding styrofoam to their tank is that they will use an unsafe glue for an aquarium or they will not add rocks or clips to help secure the styrofoam in their tank.