Would it be possible, under ideal conditions, to freeze water with no air trapped in it so that the solid ice would have a neutral bouyancy?
It’s not trapped air, it’s just that the water is less dense when it freezes.
Ice doesn’t float due to trapped air but because water expands as it gets close to freezing - it has lower density than the water it floats in. You’re not going to achieve neutral buoyancy ice via any special freezing technique.
Thanks, guys.
I’m pretty sure neutrally buoyant ice is precluded by the nature of chemical states. Most solids have molecules more tightly packed than their liquid state, and so would sink. Some substances (of which water is the best known example) expand when they freeze, due to their polar nature, therefore they float.
Neutral buoyancy means you have effectively the same overall density (your weight is equivalent to the weight of a similar volume of the surrounding medium). I’m pretty sure I’m missing a qualifier there for total accuracy, but it should be true in most cases you’ll encounter here on earth.
There are a variety of alternate crystalline structures that ice can assume if it is formed under the right temperature and pressure. Many of these are denser than water.
What a shame to find that Ice IX cannot exist at atmospheric pressure and temperatures. 
The easiest way to make neutral buoyancy ice would be to use heavy water.
Thanks, The Hamster King. Am I reading you correctly if if you are systalline aying it is possible with the right crystalline structure? Is that actually possibe?
I don’t think that that follows from what The Hamster King said. Anyway, I doubt whether any of those exotic forms of ice would survive for long in put into water at normal temperatures and pressures.
Sorry for the gibberish. I was on a wireless kb last night. When the batteries get low, it gets stupid. Anyway, thanks for the info.