Hot water seems to massively increase the solubility of ketamine. This is very important to note for IV users- if you use warm-hot water you can dissolve, 400mg/ml of ketamine. As the water cools, ketamine will precipitate out until it reaches room temp and around 200mg/ml. So PLEASE prep your ketamine shots using cold (sterile, from a break open vial & run your ket through a .2ug micronfilter) water and if you boil your water or something for IV then PLEASE let it return to room temp before you start mixing shit up, then leave it to cool for another 15 minutes in the barrel (unless you have scales, are familiar with your source, ymmv etc) just to make sure.
I've both heard the horror stories and seen the damage done by injecting ketamine solutions with the ketamine literally precipitating out of the water as it cooled in the barrel attached to the widegauge-needle injecting the solution + ketamine hci IM. Brutal shit