Hardening off is the process of slowly acclimating young plants or seedlings to a new environment. This is primarily needed when the covered starter kit is used as there is a significant difference between the environment inside and out of the mini greenhouse.
Because we are transitioning to an indoor system vs outdoors the hardening off process is much faster - 3 to 4 days vs 10 to 14 days for outside.
Step 1 - The first day avoid watering your plants and open up the vents completely to allow more airflow into the greenhouse. Also remove the light to reduce heat build up. If you don't have vents on the basic germination kit, simply remove the cover all together.
Step 2 - on the second day place the tray in a cooler area of the house and remove the clear dome from the plants completely for a few hours at a time. Keep a close eye on the seedlings - if any sign of wilting appears, replace the dome on the tray and replace under light for a few hours until any sign of wilting is gone.
Repeat step 2 until the plants are able to withstand being out in the open without showing signs of temperature change - usually two days is sufficient for indoor plants.
Step 3 - transplant the seedlings to the system. Keep an eye on your seedlings - especially the more mature tomato, cucumber and pepper plants as they tend to be more susceptible to changes in temperature.