Stalagmite of ice

I have a couple of poly tanks under the back deck to hold rainwater from the roof of the house. When they are full of water it runs up and out of an overflow pipe. We had a bit of rain a couple of days ago, the tanks are full and a bit of water seems to continue to overflow. When I went out this morning I discovered that a stalagmite of ice had formed on top of the ice that had frozen on the bucket being used to catch some of the overflow of water. I thought it a bit unusual to find an inverted icicle.

Garry