I was wondering if anyone has used the 30 cm (length) cooltubes and if it is possible to use them in a micro grow with a 250w bulb. And also if all kind of bulbs will fit into them. In some growshops they mention that these cooltubes can be used with bulbs up to 400w but i doubt it. My main concern is if they will work SAFELY with 250W bulbs. Some links to see the exact descriptions of the products. Cool Tube Reflector 30cm Ø125mm Professional Grow - Cool Tube 125mm fittings 30cm Lighting Kit HPS Flower Sylvania 250w + Cool Tube 30cm | growland.co. Cooltube 125mm/30cm / VALAISTUS - Heijastimet / ituhippi