please help

my plants are only about a week old and they have a yellow tint to them...and are very slow growing...they are not a lush green like i am use to seeing...watering is not the problem , i use a moisture meter...can someone please help me with what ohter problems i may have going on...thanks scott

temperature? soil? nutrients? usually yellow tint is indication it doesnt have enough nitrogen. but it could have nutrient lock out if there is too much N in soil. Are the stems or branches purple?