These heat mats are best used with seedlings in early propagation. By keeping your media warm throughout germination and early sprouting, our plants will grow faster and healthier. Exposing young plants and/or seeds in germination to low temperatures will(!) stunt growth and can even kill off your plants. Don't take the risk!
Lastly, these mats only draw a max of 20 Watts. A very efficient option for any grow.