The short answer is no! It’s not safe to put Orbeez (also known as water beads) in a fish tank, fish bowl or aquarium.
This is case regardless of whether the Orbeez are hydrated (enlarged) or dehydrated (in their dry state). It’s also the case with all water beads, no matter their size (as there are many different sizes sold).
What Might Happen If I Put Orbeez In My Fish Tank?
Your Orbeez may be mistaken for food and eaten by your fish. They may also break apart over time, and then the slush that forms may be mistaken for food. They may not be eaten at all, and instead become a breeding ground for bacteria (aquariums are obviously not sterile).
What Will Happen If My Fish Eat Orbeez?
This depends on whether your fish eat them in their dry state (just after adding them to water). Or whether they eat them once they are fully hydrated (after they have been soaked for a good 4 hours).
It also depends on the size of the fish as smaller fish are at much greater danger.
If eaten in their dry state, then death is the most likely outcome for almost all aquarium fish. The beads will swell up inside the fish and block it’s digestive tract. The beads may swell to the point that the digestive tract ruptures.
If eaten in their fully hydrated size then the chances of survival are better, but still not great. If your fish has eaten a hydrated Orbeez then there is a chance it has broken it down into smaller chunks with its teeth, and then these smaller bits might pass through your fish safely.
The same applies for Orbeez that have broken down into a slush (this happens if the Orbeez are left under sunlight for prolonged periods of time – the UV radiation causes them to break apart). The slush may be mistaken for food, but will hopefully pass through your fish as it won’t expand any larger.
How Can I Tell If The Digestive Tract of My Fish Is Blocked?
If your fish stops eating then this is a sign that there is a blockage somewhere along the digestive tract.
If your fish visibly appears swollen/bloated then this can also be an indication of a blockage.
What Should I Do If My Fish’s Digestive Tract Has Been Blocked By An Orbeez?
You can either have your fish humanely euthanized, or you could try to help your fish pass the Orbeez. We do not have experience with this, so cannot recommend a method. However, Epsom salt has been used to treat constipation in fish so this may be an option.
How Should I Euthanize My Fish?
We recommend using clove oil as it is a sedative at high doses.
Place your fish in a small container and add clove oil before mixing. The amount of clove oil will depend on the container and also the size of the fish. Generally, 10 drops per liter is a good amount.
The clove oil will euthanize your fish within two hours. However, you can ensure death by then placing the container in your freezer until it is frozen.
Don’t skip the clove oil step and go straight to the freezer as this is not humane for the fish.
What Can I Use Instead of Orbeez?
Your best bet is marbles, as these have the same shape as Orbeez. They also come in different colours. They won’t float in the water or look quite as pretty, but the won’t get eaten and are much safer!
It’s important to note that marbles don’t make a good substrate for fish tanks or aquariums. So make sure you use something suitable for the fish you have (sand, gravel etc) and then use a few marbles to make it pretty.