!THIS! is seriously no HR: but after fumbling around with this for a while i just switched to eyeballing, may it nasally or rectally administration.
The crystals are usually big enough to know, that you don't ingest large amounts with 1-2 of them (regarding the overall amount you're having), so i just upped the dose if it wasn't sufficient.
B-F, even if it's the pure one, isn't as hellishly potent as regular Fent, so one must have zero tolerance (then, what the f#!k are you doing with it, anyways?) or zero intelligence to OD on it.
As said before, this is not to be taken lightly, but at least for me, it worked.
And regarding the storage question: i stored mine as powder/crystals, not dissolved in some liquid, just at room temp without any preparations inside a closed container. I wouldn't to this with big amounts of this compound, but since i never had that much to play with, i really didn't bother.