Anyone else veggin under 600W MH?

Just a few quick questions for anyone who has experience vegging under a 600W MH...

If you look at the pictures below you will see my set-up. My plants all seam to be handling the 600 well, no heat stress. In fact once I moved them under it from my T5 they took off.

It is air cooled and I have my ballast set to 75% power 20hrs on, 4hrs off. Temps stay between 67-75degrees and RH stays steady around 60%.

They are approximately 16" away from the light. When I put my hand under the light it's really not hot at all. I feel like I could move them closer, like 12" away.

First, can I move them closer? I know it doesn't feel hot but I feel like that might be decieving because of all my fans. How close do you guys run your HID lamps in veg?

Second, maybe I should just leave them about 16" and turn my ballast to 100% power.

I just started this grow in a new location with all new equipment. I started from seed so I am trying to speed up the process by using the 600 instead of my T5s. Once I get ready to flower, I'll take clones, pick out a mother, and start veggin under my T5 again.

What are other people's experience using the MH as compared to the T5? I see a lot of people rave about them, and I understand their benefits, but I feel like the 600W MH completely blows them out of the water as far growth rate. In fact, once I start growing from clones I believe the MH would actually veg them too quickly and big for my needs.

If I knew there was such a big difference in growth rate I would of used it sooner!

Right now you don't need it closer . You 600w provides more lumens than a T5 . I would keep it where it's at . They will get bigger and you have plenty of lumens hitting each one even at 18" above . Sit back and watch it grow

I would wait till they get a little bigger if that Pics is current, they still looking young...How many you gonna Flower at one time, and will you still be using this setup/space?

Peace

Nice Looking Setup m8

Those do still look young to be under that much light, but if it is working hey let them go. I will say that I usually veg under my t5's but on my last grow I ran out of light and used my 600 mh and they took off and grew about 25% more.
gl have fun

I used a 400MH from seed, they seem to love it they're 1.5ft tall a little over a month from sprouting. The stems and nodes are super thick, the main stems at the bottom are more than a half inch thick already. Keep it a good 1.5ft-2ft away make sure you have a temperature gauge in there you don't want it to go high in the 80's or 90's that will burn them and stress them out if not do more damage.

BTW I just kept my ballast at 75% for the first 3 weeks, 100% from there on out... I think I will do 100% from day 1 next batch.

That is a current picture. All the more established plants were experiments while I was getting everything set up, a test batch if you will. I have 7 seedlings actually worth mentioning. 4 Bubba OG Kush, and 3 Headband. I have another 4x4 tent with a 4' 4Tube T5. I plan on flowering my 4-6 Plants, taking a few clones from each before I flower. I still have a few seeds of the Bubba and Headband in case of emergency. I'm mother hunting and trying to get myself perpetual. They seam to be doing fine, I'm just goint to leave them the distance they are. In another week or two they will be going into their final pots and I'll probably toss the bag seedlings.

I haven't had to worry about temps. Hottest it gets is mid to high 70s. I'm lucky in that respect, I'm in a cold unfinished/unisulated basement. It stays 50-65degrees year round so I actually have issues keeping my temps UP sometimes. The temp dead center under the light is 78-79degrees steady. RH is pretty stable, stays around 60 but I have to make sure I fill my little humidifier each day. If if runs out it's not a huge deal, it doesn't get to low since my exhaust/intake are both on very low.