Weird Ice Cubes

My refrigerator has an ice cube maker, but it has never worked. We could have looked into getting it repaired, but, since we aren't sure about our water quality, we have used ice cube trays instead. One of the interesting things about using these trays here is that a good percentage of the time, we get strange ice cubes, ones that stick up, rather than are flat or rounded. Even more interesting to me is that these upward spikes don't all go in the same direction. They are at crazy angles. I think someone explained to me once that a small jolt during the freezing process will cause an initial protuberance which then extends as the water is drawn upward along the small protuberance, like the meniscus on a glass of water. I am not sure if I completely understand it, though. Here is a picture of one of the ice cube trays. Yes, I do know how crazy it is to take pictures of your ice cube trays. Sigh.