Introduction: How to Grow Borax Crystals

About: Hi! I'm a slightly feral mountain hermit that likes to be helpful. I do community management at Instructables & Tinkercad. 🙌 Want to hear me chat about making? Search "CLAMP Podcast" on YouTube or your favorit…

Growing Borax crystals is a fun science experiment that you can do easily and cheaply at home!

In this instructable, I'll teach you how to grow your own beautifully colored borax crystals using pipe cleaners as a base. The pipe cleaners allow large crystals to form on them, and they also make the crystals a little more durable in the end.

I'll also give you lots of tips and tricks for making better Borax crystals. :D

Step 1: Tools + Materials

You don't need much for this project - mostly time and patience!


  • Boiling water
  • Borax
  • Pipe cleaners
  • Thread


  • Dowels or other object to hang pipe cleaners from
  • Large heat-safe glass measuring cup for making the Borax solution
  • Heat-safe glass canning jars for growing crystals (optional)
  • Scissors

Step 2: Prep Your Pipe Cleaners

The first thing you'll want to do is bend your pipe cleaners into a compact shape. The more compact it is, the more crystals will form on the outside. If you leave big gaps in your pipe cleaners, your crystals will end up with holes in them.

Once the pipe cleaners are bent into the shapes you want, tie a 8 inch length of thread to each of them. (It you have problems getting the thread through the pipe cleaners, try a needle threader! That made it easier.) Cut away the excess thread after the knot.

Hang your pipe cleaners on the dowels so they'll be suspended entirely in the vessel you're using - not touching the walls or bottom.

Step 3: Make a Saturated Solution

A saturated solution is just what it sounds like. In this case, it means that we need to add enough Borax to the boiling water until no more can be dissolved into the water.

For every cup of water, add 3-4 tablespoons of Borax. Stir it until the water becomes clear and the majority of the Borax is dissolved. (I typically do 3 cups of water at a time.) Keep adding and stirring until the water stops dissolving the Borax.

For best results, add enough Borax that you can see a small pile of it on the bottom of the glass after stirring until the water is clear.

(P.S. If you add so much Borax that the water becomes cloudy, your crystals will be cloudy as well! Add more boiling water!)

Step 4: Assemble and Wait!

If your water has cooled down, I highly recommend microwaving it until boiling temperature again - that makes the best crystals!

Place the dowels over the container and immerse the pipe cleaners into the saturated solution, shaking them a little to get rid of any air bubbles.

Once you're happy with their placement (make sure none of them are touching each other or the edges of the container), cover the container loosely with something to keep it warm longer. (Slower cooling also means bigger crystals!)

Place it in a safe area where it won't get jostled and let the crystals grow overnight.

Step 5: What It Should Look Like the Next Day

The next day, you'll notice LOADS of crystals forming on the lower sides and bottom of the container. Your pipe cleaners should also be covered!

Two notes about this batch:

  • I threw one pipe cleaner in and let it rest on the bottom, just to see how it went. It worked well, but was hard to pry off the bottom. It has a flat side if you're into that!
  • The dark red pipe cleaner did not want to accept many crystals. No idea why. ¯\_(ツ)_/¯

Step 6: Dry the Crystals and Enjoy!

Pull the crystals out of the solution and lay them on paper towels, switching the towels out when they become damp.

Let the crystals dry thoroughly before messing with them too much. I left mine in the window for an afternoon and they dried out really well. :)

Once the crystals are dry, they're much less likely to break or crack, and will also sound like glass when you tap them together.

Step 7: Tips and Tricks for Growing Borax Crystals

I tried this multiple times so I could give you some tips on what you should and shouldn't do. :D

Less crystals in a container = bigger crystals

In my first batch, I used individual canning jars for the crystals. As you saw, I crammed 7 pipe cleaners into one measuring cup when I made this instructable. I can definitely say the ones grown individually had larger crystals and more of them.

Don't try to add more Borax once the pipe crystals are in the solution

I attempted this on one of my first tries. I don't recommend it unless you want it to look like one half of your crystal has been covered in lumpy snow. :P

Try to hang the crystals close to the bottom of the container

This was something else that seemed to grow bigger crystals. The pipe cleaners closest to the bottom in the measuring cup definitely ended up with more crystals than the ones hanging near the surface of the solution.

Always, always start with SUPER hot water

Every time I let the crystals start growing in less-than-crazy-hot water, I got pretty meh results. Smaller, cloudier crystals and much more growth on the actual container.

You can reuse the Borax solution over and over!

Bring it to boiling in the microwave, and add more water and Borax as needed. That's another reason I like using the pipe cleaners - instead of putting food coloring into the solution and getting many crystals of the same color, you get tons of colors at once!