wow you are a light weight.. 20mg of psilacetin, I'm guessing that is a new term for 4-AcO-DMT? (sorry, this is my first post).
I'll assume you have the fumarate salt, rather than the freebase. That's equivalent to about 11.0mg psilocin, 15mg psilocybin, or a little over 1 gram of dried P. cubensis, assuming the figures of 0.60% psilocin and 0.63% psilocybin by weight on erowid are correct.
I have all of this laid out on an excel spreadsheet, p.cubensis is to psilocin is to 4-ho-dmt is to 4-aco-dmt fumarate, if anyone wants it.. and I know it's all correct cause I'm a chemist and I'm never wrong.
I made the chart because I was jealous of those in the recent study who had mystical experiences with 30mg psilocybin, and the chart informed me that equals roughly 37.5mg 4-AcO-DMT fumarate and I must say the experience confirmed that in spades. This is a great dose..
Equivalent to just over 2 grams of P. cubensis according to the chart but I'm starting to think that number is low and the researchers that erowid pulled those numbers from had better quality mushrooms than what is normally pulled off cow shit and found in the streets these days. An ounce of mushrooms would be 65.4mg going by these numbers!