Okay a foot it is. Just raised the light to 1 foot above top of plant. Thanks for the input everyone, i really could have done some damage.
Hmm ph is kinda high for a full water system. Should be closer to 5.5 Here's a ph chart for water gardens http://www.pnwgardensupply.com/files/images/soilless_ph.gif It also look like you have salt burns on the leaves but it could also be heat stress from the 400 being so close. The 400 should be ok at about 10-12" from the top of the canopy
There are many sites that have info on FIM, just do a Google search and pick the one that you like :- )
Yea Direwolf has a great thread on this site about FIMing. I clipped 80% of the new growth coming in at the top yesterday. My hope is that it will become 2 new fan leaves and then I will FIM the new growth between them too!