Hello everyone, I am actually posting this on behalf of my partner who is not really used to Reddit/forums. So from what I understood from her was that she already has the formed crystals but they're somehow wet. So she needs the maximum temperature she can heat the substance before compromising the following compounds. I might not be explaining it properly so if you have any questions I can relay them to her. Thank you all ahead of time .
Nickle II Chloride hexahydrate
Nickle II Nitrate hexahydrate
Coper II Nitrate pentahemihydrate
Lead II Nitrate