Making your Orbeez (aka water beads) glow in the dark can be a fun sensory play experience for your children.
That’s why we put this guide together – it covers the DIY method getting your orbeez to glow by easy to find using fluorescent materials (such as tonic water).
Fluorescent materials only glow in the dark under a black light (often referred to as a UV or UVA light).
We’ll also discuss phosphorescent materials such as zinc sulfide and strontium aluminate (think glow in the dark stars).
How to Make Orbeez Glow In the Dark with a Fluorescent Material and A Black Light?
This is the simplest way of getting your water beads to glow in the dark.
You’ll need three things:
- Transparent orbeez/water beads (also referred to as clear water beads)
- A black light (also referred to as a UVA light)
- Fluorescent material that is dispersible in water (easier to get than you would think)
What Is A Fluorescent Material?
A fluorescent material glows when exposed to UV light, but this glow ceases as soon as the light is removed.
What Fluorescent Material Should I Use?
Tonic Water As The Fluorescent Material:
The easiest method is to use tonic water that has at least 5% quinine. You should be able to find it in any supermarket (try Schweppes or Canada Dry as both these brands contain more than 5%).
Helpful tip: Try diet versions of tonic water to prevent your orbeez being sticky to the touch.
Quinine is the ingredient in tonic water that glows when exposed to UV light.
Simply grow your orbeez in tonic water until they have expanded to their full size. They won’t grow as large as they would in pure water, so leave them for a good 4 or so hours to ensure they have reached their maximum size, and then drain the excess tonic water.
This method will make your water beads glow blue under a black light.
Highlighter Fluid As The Fluorescent Material:
Most highlighter ink is non-toxic, however, it’s best to buy highlighters that specify they are non toxic to be on the safe side.
Even with non toxic ink, it’s also important to make sure your kids wash their hands after playing.
Helpful tip: Choose yellow or green highlighters for the best results.
Once you have your highlighter ready, you’ll need to carefully break it open to retrieve the sponge from the inside (this is what contains the ink).
Then cut the sponge open and mix the ink in a container of water. You don’t need much ink but you can’t go wrong by using more than you need. So, make sure to squeeze all the ink out. You can use a second highlighter if you plan on making a lot of glow in the dark water beads.
Now you can grow your orbeez in the water until they have expanded to their full size. As with tonic water, they wont grow as large as they would in pure water, so make sure to leave them for at least 4 hours to get as large as possible. Then drain the excess fluid (or keep it for now just in case you need more water beads later on).
This method will make your water beads glow yellow or green under a black light.
Vitamin B12 As The Fluorescent Material:
Vitamin B12 is a safe, non toxic and water soluble vitamin. It’s probably the safest method of making glow in the dark orbeez.
Just make sure you get it in a form that is easily dispersible in water. You don’t want to have to spend time breaking tablets apart with a hammer!
Once your have your vitamin B12 tablets, simply dissolve them in water. Mix well and add the water beads. Allow them to grow for at least 4 hours and then drain the excess liquid.
This method will make your orbeez glow yellow under a black light.
What’s Next?
Now that your orbeez have been prepared you’ll need to get your black light ready.
You can go with a battery powered black light torch or a more powerful mains powered unit. Be careful if the latter is used due to the dangers of mixing electricity and water.
Close the curtains so the room is dark and then light up the water beads with your black light! They’ll glow as the light shines over them. Turn off the light and they’ll immediately go dark.
This makes a fun learning experience for your kids. Not only can you teach how osmosis works (from growing the beads) but also how fluorescence works. You’ll be introducing a number of great scientific words to their vocabulary too – ultraviolet, transparent, quinine and so on.
What About Phosphorescent Orbeez?
Phosphorescent glow in the dark water beads don’t need a black light to make them glow. They soak up sunlight and then emit it a glow over time. They can be made by using zinc sulfide or strontium aluminate.
Unfortunately, it’s not easy to make water beads glow in the dark with a phosphorescent material like zinc sulfide or strontium aluminate. These compounds don’t mix well with water and they are beyond our DIY level!
However, you can purchase water beads/orbeez which have been manufactured using one of these two compounds. The materials are non toxic and safe.
Zinc sulfide is the most common phosphorescent compound used in glow in the dark toys. You have probably seen it used before in glow in the dark stars.
The upside of zinc sulfide is that it is very cheap. The downside is that it doesn’t glow for very long and it’s not that bright.
Strontium aluminate is a newer and less common compound. It’s more expensive but it glows up to ten times brighter and longer than zinc sulfide.
It’s up to you which type of phosphorescent glow in the dark water beads you get. You can find them on many online marketplaces such as Amazon, eBay and Aliexpress.
How to Make Glow in the Dark Water That’s Safe to Bathe In?
You might want to try skipping water beads entirely and just use the glow in the dark water as a fun bath time for your kids. As this will allow your children the opportunity to drink it we’ll have to stay away from using tonic water and highlighter fluid for the fluorescence.
Instead, we can use vitamin B12 as we did before. This is a completely safe vitamin with no tolerable upper limit set (meaning you can have as much of it as you like without any negative effects). Any excess B12 leaves the body in urine. You won’t need to worry about your child absorbing it through their skin or drinking it (although it’s best not to drink bath water in general!)
Hopefully, you’ll have some easily water soluble B12 to mix into the bath water. If not, then make sure you crush the tablets into a fine powder before mixing them into the water. You don’t need much to achieve a decent glow under a black light.
What Other Things Can I Do With My Blacklight?
You can show your children all sorts of everyday items that glow under a blacklight. Some interesting ones include:
- Bank notes
- Banana spots
- Tomato sauce
- Laundry detergent
There are many other everyday household items that glow in the dark. Have fun finding them!
