I'm going to a party tomorrow and some proper ket head who I'm pretty sure steals his stuff from a vet is gonna give me some real cheap so with the fairly large amount that I'll have I wanna know how to stay safe. I don't mind overdosing on opiates because it doesn't scare the shit out of you (in my experience), but I don't want to be traumatised so I'm actually going to take some precautions. And besides things are getting better nowadays, so why shouldn't I? 
Numero uno, I know the dose for my weight (55 kg) is about 30mg, but that's a tiny amount about the size of a pinch of salt, so how do I actually measure it without a mg scale? Just like put a bit on the tip of my finger or make lines? and how big should the lines be?
Numero dos, how often should I redose? I heard you're meant to redose every 15 minutes or so, but I also heard that snorting ket lasts about an hour, or an hour and a half if you eat it. I'm so new to this shit though I really have no idea, never been on the party drug scene or anything other than pills, and I don't go out and party with them anyways, but that's irrelevant.
I've never done ketamine as I'm sure you can tell and I'm not really sure about what it even does other than it's a dissociative, but I've done DXM a few times before, and even though it was pretty shit, it wasn't terrible (other than the vomiting).
Thanks in advance fellas

Numero uno, I know the dose for my weight (55 kg) is about 30mg, but that's a tiny amount about the size of a pinch of salt, so how do I actually measure it without a mg scale? Just like put a bit on the tip of my finger or make lines? and how big should the lines be?
Numero dos, how often should I redose? I heard you're meant to redose every 15 minutes or so, but I also heard that snorting ket lasts about an hour, or an hour and a half if you eat it. I'm so new to this shit though I really have no idea, never been on the party drug scene or anything other than pills, and I don't go out and party with them anyways, but that's irrelevant.
I've never done ketamine as I'm sure you can tell and I'm not really sure about what it even does other than it's a dissociative, but I've done DXM a few times before, and even though it was pretty shit, it wasn't terrible (other than the vomiting).
Thanks in advance fellas