Comments on: How to Grow Salt Crystals

on 11/17/2009 I remember doing this as a kid all the time. I don't remember using the paper clip or fishing weight or even the pencil and string? Does it work without these? Also, wondering why anonymous suggests putting petroleum jelly under the rim of the jar. What's the purpose of this? Also, just a note, I used plastic cereal/butter bowls as a kid instead of glass and it worked just fine. Thanks!

on 6/28/2009 The surface of the charcoal is covered in tiny holes which act as a nucleation site. The food colouring is mostly for show, but the fact that the crystals show absorbtion of the colour indicates that they contain "water of crystallisation".

on 5/18/2009 What effect does the charcoal and the food coloring have upon the experiment? How scientific is it to include food coloring, I assume it's just for show. But the charcoal- I really wonder what the effect of the charcoal is. I think we'll do it with and without- I'm a learn-by-reading kind of girl, I wish you would have addressed the reason for the charcoal.

on 11/13/2008 im making two diffrent ones i didnt get it so one i put 1 table spoon of salt and the other one 2 tablespoons i will tellyou how it goes lol one is blue and one is orange

on 1/25/2006 If you're doing a science fair project, you might want test out your experiment a couple of times before your final. Sometimes your results on the first experiment are less accurate.

on 3/24/2008 Salt crystals will grow up the sides of the jar as evaporation proceeds. After the water cools down, smear waxy lip balm or petroleum jelly around the inside of the rim, above the water line.

on 11/23/2008 If you want your crystals darker, add three to four drops of food coloring to see your crystals in a darker color.

on 1/28/2008 We were about 20 college students trying to grow crystals from NaCl (salt) and water. We started with distilled water (thinking it was pure), but forgot before we started warming the water to add the salt. We took too long in the process, and the temperature was not constant either. The worst part was having a few tiny pieces of an unknown black material in the salt. They were not removed and counted as impurities that ruined our projects. None of us succeeded at our intent.

on 2/14/2008 I would suggest that if you're doing a science project, don't use the food coloring. You could only see the shapes and you couldn't describe the color. That's goes for the other crystals, too! :) Wish me luck on my next Science Fair project!