my seedlings are now 12 days old and still only have their 1st set of leaves and a small set of 2nd set. the bottom leaves are reeally yellow and some are starting to get brown spots on the ends. they havent really grown in the last week. not sure what im doing wrong i got them in fox farm light warrior undr 250w mh about 2 feet away. ph is about 6.6. no nuts have been used yet. any input is greatly appreciated thanks