Hey Highway; Look around for a Metal halide bulb for the veg space (if your 400w ballast is electronic, it will run both MH and HPS) that puts out 6500k spectrum. Most MH bulbs put out 5000k which isn't as good because it has too much green light in it. But I have seen several that produce 6500k which is ideal for vegging. Grow Mojo for your cloning
Also make sure to get some Clonex gel as it helps a lot with rooting.
Growdude: I am surprised that the guy would say 70f, but everyone has their own way of doing things.
I'm not saying you or he are wrong, this is just my experience. I have had several situations where I found the 77-80f range produced better results for myself and others, without the issue of slime buildup. My Bro has an ez-cloner 40, I believe, and he was having a hard time with it taking a long time to get the cutting to root. He uses Clonex and has good aeration but wasn't getting but about 50%success and it took several weeks. His temps were in the lower 70s. I put the meat thermometer in it and we ran the temps up to right at 79-80f and he immediately went from 50% to 99% success and they were rooting within 7-9days.
I actually discovered this temp usage by accident with my bubble cloners. I was having trouble cloning in lower temps, and thought it was not enough light so I closed the door on my cloner cabinet and turned on another bulb in my T5 fixture. within a week I started seeing root growth, and I noticed the temps were staying right around the upper 70s. The second time I did cloning, it was warmer outside and I was having trouble keeping the temps down in the cloner so I turned off one of the bulbs and opened the cabinet to let in better air flow. The temps came down and the cloner stayed right at 80f. I was concerned about not having enough light but tried it anyway as having more light increased the temps. within 5 days I was seeing root bumps and within 7 days, I had new roots shooting out everywhere.
I continued to use this method of lower light and 77-80f temps with 95-100% success, and no sign of slime in the cloner. After this was when my Bro told me he was having trouble and I changed his to the higher temps. He has had solid success ever since (for over 2years now). I have told a couple other people who have had similar, better results. Maybe its strain specific with either my results or the cloner guy's results, or some other variable that one of us has missed, I don't know.