Diesel ryder

I'm pretty new to growing but i am just worried about my plant. It's still a seedling and is 12 days old (i believe, i can't tell how old it is because i had some trouble with germination so age may be 3 days or so off). She has a little bit of yellow tips and some brown on the side of the leaves. It's not too bad, doesn't look like a problem. I believe the brown on the side was from too much nutrience, (followed the back of the directions which said 1 ½, tsp per gallon), which i remember reading somewhere that all types of cannabis require different amounts of nutrience so i jumped down to using only 1 tsp and am waiting to see how she likes that. I'm using an aerogarden which has a 1gallon resevoir and i leave the pump running all day with the light on 18/6. I've been giving her a weekly feed of 3-2-4 and then am going to switch her on to the 2-3-5 for blooming. I got an oscilating fan and have the aerogarden surronded by mylar. Here's some pics of her, tell me if you think i need to do something more than what i am doing.
http://i540.photobucket.com/albums/gg358/shenjai2/mms_picture-1.jpg
http://i540.photobucket.com/albums/gg358/shenjai2/mms_picture.jpg

It looks overwatered actually... But its not a big problem... There's no deficiencies in the plant, she's looking great, just let it go... Nature is never perfect...

So should i not leave the pump running and what time frame should i leave it on if so.

I've never grown in an aerogarden, but I do use aeroponics... I think you should leave the pump running.... It wont take long for them to get bigger, and they'll use more water anyway... So don't stress...

Thanks a bunch lacey.