Clones under mh lighting how far please?

Hi everyone, I've read that most people use fluoresents for their cuttings but I'm hoping I can make use of my current lighting system. I'm using 400w hps for the flowering and a 250w mh for vegging. I have my propagator (unheated) about 3-4feet away from the 250w light (and also behind it if you know what I mean). I don't really want to rig up a third light and would like to take advantage of the 250w mh so how far should the propagator be do you think? Thanks.

Clones need very little light until they have grown roots. Having said that, the usual method of setting your light is to hold your hand just above the plant/cutting and if you can feel the heat from the light on the back of your hand, it is too close. Once it is comfortable for you, it will be comfortable for the plant. Green mojo dude. W