Decorating Your Goldfish Tank for Halloween

Click here to see My Halloween-Themed Aquarium!

Halloween is just around the corner, and that means people everywhere will be busy decorating their homes for the holiday! But why stop there when you can decorate your fish tank as well?

Typically I don’t like a lot of decorations inside a goldfish tank because (as you undoubtedly know) goldfish are clumsy! They can get hurt brushing up against rough surfaces, they can get stuck trying to fit into a hollow ornament that’s just not quite big enough for them, and harmful bacteria can build up in hollow ornaments or deep gravel. Even with all this in mind, I still really wanted to decorate my goldfish tank for Halloween this year, so I came up with a few ideas that won’t pose a threat to my clumsy fish.

For Inside the Tank
Choices for decorations inside the tank are limited, but there still are a few options.  When selecting any decoration for inside your tank, just keep in mind that goldfish are clumsy!  Regardless of where you buy them, all in-tank decorations should be cleaned well before use.  I find that dipping them in boiling water works well.

Flat Glass Marbles

I don’t use gravel in my tank because it’s difficult to keep clean enough, and it can harbor nasty bacteria.  Instead the bottom of my tank is painted black on the outside, so it has a nice finished look without substrate.  So to decorate for Halloween, I bought some flat glass marbles from Michael’s craft store in orange and black colors.  These will be safe for my fish because they aren’t sharp and they aren’t small enough to get stuck in their mouths (as gravel often does).  I simply scattered these glass marbles on the bottom of my tank.  If you have black sand in your tank (many people like the black Tahitian Moon sand by CaribSea) you could use these flat marbles in just orange to add a pop of Halloween color.  If you have natural colored sand, you could use both the orange and black colored marbles.    

Skull Ornaments 

I was well aware that I’d have to be careful selecting an ornament that wouldn’t pose a threat to my fish.  Most tank ornaments are made with holes in them because they’re designed for small fish to hide in.  This isn’t necessary for goldfish though, and they can even seriously injure themselves by trying to swim through the holes.  So I had to select an ornament that; either didn’t have holes, had holes that allowed ample room for my fish to swim through, or had holes that were much too small for my fish to fit into.  I found a life-like human skull ornament at Petco that I really liked and had small enough holes that my large goldfish wouldn’t be able to fit into.  I normally don’t like to use hollow ornaments because they can become a trap for bad bacteria.  However, since I’m only using this ornament in my tank for a very short time over Halloween, I’m not concerned about this.  I will also be removing it from the tank at each weekly water change to clean it out well.  It’s important to select only ornaments that are made specifically for aquarium use, because other ornaments can contain harmful substances that could leach into the water and kill your fish.  Of all the types of ornaments pet stores usually offer, I think a simple skull is the safest for most goldfish tanks because it’s typically a little more open than other ornaments (like tree branches or pirate ships) and thus the water inside is less likely to become stagnant.  With any hollow ornament, adding an air stone inside it can help keep water moving through it consistently.

Orange and Black Fake Plants
When selecting a fake plant for a goldfish tank, I’m always careful to pick ones that are soft and lack sharp edges.  Goldfish can rip their fins and damage scales by rubbing up against the sharp edge of a plastic plant.  As with all aquarium decor, it’s important to select only fake plants that are made for aquarium use.  I found a really nice tall bright orange plant from a local aquarium store.  I normally don’t like unnatural colors for fake plants, but this is Halloween decor, so different rules apply!

For Outside the Tank
There are many more options for decorating outside of the aquarium.  You can use a wider variety of objects since they won’t be coming into contact with the aquarium water and thus won’t be posing any threat to the health and safety of your fish.

Window-clings
Window-clings can always be found at any place that sells Halloween decorations, and these would look awesome either on the front glass of the tank, on the back glass, or some combination of both!  This can be a fun way to involve children in the decorating too!

Paper Cut-outs
I wasn’t able to find exactly the right window-cling that I wanted, so I drew and cut out one of my own using black construction paper.  I made a black cat silhouette for my tank.  This is a great alternative to window-clings if you can’t find exactly what you’re looking for at the store.

Spider Web and Spiders
I found some fake spider web material at the dollar store, and it even came with some little plastic spiders!  This can be draped over certain areas or corners on the outside of the tank, it can be hung from the tank stand, or it can even be hung from the wall or ceiling over the fish tank.  You may want to use a little bit of tape or some tacks to hang it though, since it only clings well to rough surfaces.

String Lights
There are many types of fun Halloween-themed string lights that you can hang in many different configurations around your fish tank.

Get Creative!
There are any number of great Halloween decorations you can use on the outside of your goldfish tank, so go shopping and see what you come up with!