using a 600watt metal halide with cool tube

im using a 600 watt metal halide with a tt100 extractor fan with ducting,it will change to 600w hps when flowerin begins,i want to know how close can i get my metal halide to the plants for now,and for when flowering begins..there one week old ight now! cheers!!

cheers mate! as they might say acrosss the atlantic...

can u tell me how close i can get my light to my plants without burning them..??

As close as they can handle...its not an exact science. Basically keep the temperature at your canopy level below 85F, so if you have good airflow to remove the heat between your plants and the lights you can get them closer, but if its just stagnant air sitting there you'll have to keep a larger distance. Take a stick and mount your thermometer at the same level as your tallest plant and let it sit for 10-15 minutes and that will give you a good idea of if you need to raise or lower your light. Also adding an occilating fan to blow air around strengthens the stem and keeps the heat from building up in the space between the light and the plants