"Does it go to say that the longer it spends evaping the bigger the crystals will be acheived and does this also mean maybe swim should use 5 times the amount of the initial alchol? and is a cold acetone wash important to wash off any left over IPA ? any help would be greatly appreciated."
1.yes
2.experiment with your choice of dry alcohols,
3.swim prefers to wash with cold dry acetone when the crystals have reached the final stage of recrystallization, and 25% or more of the mother liquor has slowly evapped.
Leaving the container there for ALL of the solvent to evap is leaving impurities trapped inside the outer layers of the core, when a crystal grows in the mother liquor it's basically pushing the impurities out into the mother liquor (from the core), the longer you leave it alone, the easier it is to perform purification at it's own pace(vibrations or rapid rises/drops in temp to the container will affect the process but nothing to dramatic) rather than forcing it by rapid cold temps. as the temperature drops the solvent looses it's grip on the rest of the meth that's left in the solvent (small needle's, powder)
p.s UTFSE on "super saturating",(and recrystallizing for that matter plenty of information on this small process)