Good point about the internal reflector i could see that making a huge difference.The downside to an external reflector on a cool tube is the light has to go through the glass, hit the reflector, then go back through the glass to get in the tube and again to get out of the tube headed towards the plant. Each passage through the glass is a loss. I have seen cool tubes with the internal reflector.
Back in the day a buddy gave me a new 1500 watt MH ballast kit and new lamp that was replacement gear for stadium lights lol. I hung that thing in one of those big parabolics that look like a big umbrella lol I had 3 plants in the old krusty buckets that it was sorta centered over and several vertical 400 watt hps lights around the sides because I had them. That was a pretty epic crop as I remember, the frost from that MH was thick.If using HPS a Parabolic Reflector is the best for light coverage.
Heat is also dispersed nicely if you chose the Maxibright version with the vented top.
You’re looking for duct reducers you can get them to go from 150mm to 125mm or from 125mm to 100mm etc.Thanks everyone for the replies! I decided to go with a prebuilt cooler with an internal reflector as suggested here.
Found a decent one second hand, with cables attached to the ballast and all that fuss hehe.
I have one more question if anyone reads it, so most of these cool tubes has either 125mm or at least 110+mm diameter(the one I bought also is around 10-12 mm bigger than 100mm) and my ventilator and my ducking have 100mm. Is there something I can buy, that make them fit together? Like a 110mm --> 100 mm redactor or something Or should I just tape it from the inside and try to air tight it with tapes?