I don't know if there are any transcripts of his videos or debates where he mentions the 3 states of matter but I have seen it in the videos a couple of times.
It is always a quick smatter with no depth used to make you feel all warm and fuzzy about a correlation between trinity in nature and the Christian Trinity. Not like Hovind goes into any depth on anything else anyway but I have only seen him talk about it with an superficial treatment.
I wouldn't waste your time watching the videos to find it.