Plants keep dieing in rockwool cubes

[MACHINE]

yeah, the first time i did cook them.. thermometer registered like 37C (basically just under a 100F).. I suppose a heating pad would be in order if you are using flourescents, since they give off no heat.. but the heat coming off regular 100w bulb at about 8" is keeping the temperature inside at 25C (77F).. My humidifier was registering 99% even though both vents were open. I know it is high but i rather be too moist then too dry at that stage.. I did it like that for the first week for 24h light.. then switched to 18/6 where they are now..

MACHINE Reviewed by MACHINE on 01-11-2010. Plants keep dieing in rockwool cubes ok so all my plants keep dieing when i put them in rockwool cubes. i start the seeds in a wet paper towel then put them in cube. the start off good then about a week after i put them in the cubes the stems turn purple and the plants die whats happing and how can i fix it. also i have them on a heating pad and in the moister dome. Rating: 5

[MACHINE]

sorry didnt mean to say humidifier.. my humidity tester registers 99%..