Yeah, I found the limit with my 120 yesterday. I was on my knees staring into the tent and I noticed some of the hairs on the biggest bud were leaves. The finest new leaf growth on the tallest plant was getting singed! I quickly took the light up a few inches. I had been running at 9-10" (which we'll call the "veg" time) and no troubles. I am now going to raise a few more seeing how low I am in comparison to Skotty. I was reading a few old forums were people were saying 8" is optimum, but I think its a game of russian roulette, especially with a fast grower like Onyx.
Regarding seedling mat-> Im telling you its a must have grow tool in general, you'll love it. I have a cabinet and a tent going right now. I didn't have enough space to put seedlings all in one place. The seedlings grown under the exact same light in the cabinet with the mat were all 15% bigger after 7-9 days then the ones with no root heater. Its the perfect place for the heat to come from too, since warm roots allows the plants to stay more stable during swings in temperature,, the way a big tree survives deep freezing winters with long roots down below permafrost.
Regarding seedling mat-> Im telling you its a must have grow tool in general, you'll love it. I have a cabinet and a tent going right now. I didn't have enough space to put seedlings all in one place. The seedlings grown under the exact same light in the cabinet with the mat were all 15% bigger after 7-9 days then the ones with no root heater. Its the perfect place for the heat to come from too, since warm roots allows the plants to stay more stable during swings in temperature,, the way a big tree survives deep freezing winters with long roots down below permafrost.
