No question the ice is safe now. I can shine my "tactical" LED flashlight (re-purposed car headlight or something) through one of the skylight holes from and old leak and see it is at least 10 inches thick now. Freezes nice without snow on it!
In case you are wondering how to tell thickness this way: Do this at night with a bright flashlight and a tight beam. A green laser pointer would work great!
If you want to get fancy, angle the flashlight at roughly 45 degrees to the ice surface and then mark on the surface where you see the beam exit the ice and hit the water. Typically you can easily see the difference in clarity between water and ice unless the water is very clear. Measure from the flashlight location to the mark. Use a little trigonometry to get a good estimate on thickness. Diffraction due to light entering the ice and where you observe the water can be factored in too for more accuracy.
Last edited by liquidsquid; 01/02/18 10:25 PM.
