ice cubes

Here are ice cubes that live up to their name. I'm trying to get clear ice cubes. I heard if you boil the water twice then that rids the water of minerals and air that clouds the ice. I've failed three times. It occurred to me maybe water doesn't boil hot enough at altitude so I pressure cooked the water on severely high, twice each time, so that's four times in the pressure cooker and it still clouds. I'm going to try reverse osmosis water next. If that doesn't work, then I'll boil the reverse osmosis water. (twice) I'm not going to quit until I try everything. Some of these actually do come out partially clear, but not 100%.

Tovolo trays.