Dry air (particularly when combined with high temperatures) creates a vapor pressure deficit between the air and your plants' leaves. We take a look at how to take control of relative humidity levels inside a grow tent. "Growing plants prefer relative humidity levels of around 60%."
Optimal Humidity is 40-60% RH. Don't give seedlings a humidity dome unless it's very dry where you live. The RH is too high if the plants are forming wet spots on their leaves. As seedlings get older and become young plants, they want the humidity around 50% RH.
Amazon.com: KinGrow Multifunctional Temperature Humidity Monitor, Indoor Thermometer Indicator Hygrometer Gauge Home Office Garden Indoor Grow Tent: .
Growing your tomato plants indoors is a practical way to control the surrounding. Your humidity levels also play a significant role in determining successful.
Pick an optimum place to pitch your tent (answer: under trees); Minimize the sources of additional moisture inside your tent; Ventilate, ventilate, ventilate.