Fun Fire Accessory for the Kids

Hey guys! I'm just back from the cottage where I spent all day in the sun and all night by the fire. Anyway I picked up these four little fire colour change packets when I was at the fabric store just as something fun for my step brother and sister in-law (my fiancs step siblings) to have up at the cottage.
I was really disappointed with them. Our fire pit was only about 2ft x 2ft so I put two in at a time thinking this would be enough to make the flames all be coloured, but as you can see from the pictures its only a tiny fraction of the whole fire.
The package says its suppose to last for half an hour or more, it only burned for about five minutes.
It did however change the flames to a very pretty blue colour and green at one point. This was really neat and the kids liked watching a lot they had no idea what we had done but the fire made them sit quietly and watch.
If I had put all four on the fire I think that the results would have been much stronger. But over all I liked the idea and what it produced.