I don't do all that bringing them outside and dropping the temp stuff on phals... They should bloom on their own. A 18C night should so the trick, if you require a temp drop. In the summer they all bloom like mad because they get plently of light, not temp drops but temp increases. They try to bloom in the winter but poor windowsill lights hinders their blooming and yield flowers that are poorly shaped and sized. I notice a pink phal getting darker colours though. Next year I will hang fluorescent lighting so that yet get into full blooms for christmas, its just not good having everyone come over and seeing crappy looking windowsill phals, they never see them in full bloom, so it looks like me and my mom are bad gardeners.