Yeah, that light is waaaaaaaay too close and is cooking the top of the soil. I would move it up at least 2' from where it is in the picture. 400W is overkill for this stage of the grow, but if it's all you have then go with it and do everything in your power to acquire a blue spectrum bulb for vegging. If you want to stick with a one light setup you NEED to get a different bulb for vegging. Otherwise, your plants will stretch under that HPS light and you will have more hassles to deal with not to mention a lower yield in the end.
I would suggest getting a T5 for seedlings/clones. I use a 6 bulb T5 with switches that allow for either 2, 4 or 6 bulbs to be on at any time. So, you can run as little as 100W or as much as 300W if need be. I highly recommend this if you want to take your grow to the next level.
I would deff move that like 2 or 3 feet higher though lol. And possibly pick up a cheap MH bulb. I save my horti's for flowering, too expensive.