Do you recognize our salt crystals experiment from this post? It started off like this:
We wound up with nicer crystals in the bowl where the water evaporated than on the sponge itself; I’m not sure why. We plan to grow sugar crystals next, as soon as I get organized. We’re growing mung bean sprouts in the meantime, to healthy things out a bit!
Growing Salt Crystals
This experiment was super easy to set up – we got the instructions from this science kit for littles. We dampened the cute dog-shaped sponge with some water, and mixed one cup of water with half a cup of salt, as well as a little (well, a lot of) red food coloring. Then we poured that solution over the dog and left it sitting on our kitchen counter. We poured a little more solution in the bowl every day. I don’t understand how the crystals climbed up the edge of the bowl and even onto the underside of the rim. Can anyone explain that?
Update: we tried growing sugar crystals, and it was a huge hit with the kids! As with this salt crystal experiment, we were successful in growing crystals, but they didn’t grow quite the way we expected.
Have you ever tried growing salt crystals? How about sugar crystals? Did they turn out the way you expected?
MaryAnne is a craft loving educator, musician, photographer, and writer who lives in Silicon Valley with her husband Mike and their four children.
How did you do it
It’s just a bowl with salt water and food coloring left out for a few days. The sponge helps get the crystals started.
Looks good. We did sugar crystals – the good news about sugar experiment that you can actually eat the results.
We plan to try those next!
Oh. I know this… it has something to do with capillary action. The sponge pulls the water upwards and the water brings along the salt, then the water evaporates leaving the salt behind. I suppose the container has some capillary effect too, most materials do, even some metals.
Thank you, Kimira! Maybe if the container has capillary effect that explains the crystals going onto the underside of the rim?
I remember doing this as a kid!! I was so impatient to see something happening. I remember losing interest and my dad pulled it out a few days later, I was stoked! I think we made blue ones.
That is so cool! I need to do this experiment with my kids. They would enjoy it.
It’s very simple and fun :)
You got some amazing crystals! I remember growing crystals on string in elementary school. Will need to try this with my kids.
I was really happy with how well it worked out – especially in our humid climate!
That looks fun! How long does it take?
We stopped adding water after 7 days – this was a couple days after that, once all the water had evaporated. There were a few crystals on the sponge the first day!
Looks very interesting.My daughter would love this experiment.Thanks for sharing.
No, but it looks cool.
Wow! Yes I remember this experiment. What incredible results. We will definitely be attempting this one!
I wonder if we even have any local toy stores anymore. I’m definitely going to look into it. And what a fun experiment!
OH my goodness! At first I couldn’t figure out what that was…great first picture! We will have to do that!