A person came to my center today and left about about 30 minutes of floating. There was one SNAFU where I left a phone on that rang at one point, but that was not the problem. The main thing was that he was not able to make it as dark as he wanted.
As a result he was not able to go inside and see the light energy patterns that he was able to at another float room nearby. He said that Lilly spoke of these in "The Center of the Cycle".. I do recall in "The Deep Self" that he said that sensory deprivation was a a misleading term and that the senses were quite alive in the tank.
I've had some misgivings about building my own tank and offering my service on a semi-commercial basis, especially where I'm located. I'm also a bit upset that my energies are scattered amongst so many things so that I never perfect any particular one. Then again, I dont recall my float-to-relax tank being perfectly dark. And I dont think the Samadhi tanks at Spacetime tanks were either… they certainly werent soundproof.
Sigh…