If you think that the reduced heat output of the LEDs might hinder the development of the plants in the terrarium, you can get a more powerful bulb than the 50W bulb. Radiators outside the terrarium box are a great solution. If I were you, I might buy these smart bulbs for my terrarium https://www.vont.com/product/vont-bulb-color-smart-light-bulbs-smart-bulbs/. I've had these red bulbs with excellent heat output for a long time, and they don't overheat my plants. Of course, there are many different wattage bulbs on the site. But I'm writing you about these because they're the best for such purposes. Good luck with your terrarium development!