The second time I went on the Crystal Bed it was a totally different experience from the first time. This made me realize that there are a lot of variables that come into play to determine the nature and quality of our experience.
For one thing I was in a different mood or frame of mind. It was a different time of day, and what had happened to me earlier in the day had an effect. I had been around a lot more people and talked to a lot of people and probably picked up some energy from them that was different (perhaps not totally positive either!)
Then when on the bed I started thinking about the environment. I could hear sounds I didn't hear the first time. There was a different odor in the room. It also felt warmer. The clothes I was wearing didn't feel as comfortable.
On top of all of that, I stayed on the bed twice as long as the first time -- 40 minutes this time compared to 20 minutes the first time. I think this was too much for my second time. I felt very overloaded -- like all my circuits were full! I had a slight headache and actually felt queasy in my stomach as well.
Given all of these variables, I'm not sure what caused my second experience to be less positive -- maybe "less pleasant" is a better way to say it -- than the first time. But it did make me aware that there are lots of things that can affect the experience.
To make the experience as good as possible I concluded I should be in a peaceful and relaxed state of mind when entering the Crystal Bed. I should either wear ear muffs or listen to pleasant meditative music. The lights should be either off or very dim. The temperature should not be too warm in the room. I should be wearing loose fitting and comfortable clothes.
As far as the time spent on the Crystal Bed I think it varies from time to time and you have to be aware of what is going on inside you. If it is enough you will know it and you can get off before you over do it and get that sense of "overload" that I had on my second visit.