In search of clear ice, experiment

We tried different things already taking icicle formation for example.

In the First grade in Pennsylvania the most outrageous icicles formed on eaves on the entire side of the house. They were huge knobby, sometimes all bent the same way by wind but mostly perfectly straight and pointed like dangerous weapons and surprisingly clear.

We thought the clearness had to do with the way the water is deposited built up in layers, the same way commercial ice cube makers work.  

A few days ago the weather channel reported on a lake with the clearest ice on Earth. It really is weird walking on top of it. The rocks show below through glass as if the person is walking on air. The solution to the conundrum was slow freezing just below freezing temperature that allows time for impurities to sink and for air bubbles to rise.

It didn't occur to us the icicles are formed at higher (than freezer) temperature too, just below freezing or else they could not drip at all. They need to be liquid water to form, but just so, just at that precise point of freezing before dripping off, so, cold nearly freezing sluggish water. It's another of those phenomenon that occur right at a borderline, this border being the precise line where water freezes.

That's the theory.

At 12 hours the ice has not completed freezing. The tray is bundled again and returned. 

12 hours later, 24 hours total, the ice is frozen. And partially clear.

Status: Fail. They each have a patch of opacity. This is the closest I've come. The bundles might be wrapped insufficiently on the sides. 

I'll pick up a tiny styrofoam ice box, one designed for a six pack and put that inside the freezer and see if that slows down the process on all sides sufficiently. 

For now, new bundles are prepared with filtered water. It's a ten-stage filter. 

Why do I want clear ice?

I don't know. It's a bizarre challenge.