I think 30 is ok...during the early part of the summer here the temp in my greenhouse ranges from 14+ at night to a good 35 to 40 during the day...I just keep them well watered ( not in the morning, always at night ) and ventilated. Never a problem.
yea man ontario canada too im usings 3 cfls, and cool white tubes, its in the back of my shed now behind a false wall,i have a vent in but no fan just oscilsating fan
best to get some fresh air in there if you can...not sure what you are planning but if you are keeping them inside, gonna need to work in some in and out air.