major problems

i have had 2 plants grown and both plants and both have started to die at the end of the leaves when there about 3in tall

Need pictures....
nutrient problem...?...

need more info room size how old soil or hydro light what kind wattage feeds water or fetalised
how offten lots of factors
pic helps loads

the room is only a small cupboard and the soil is brand new miracle grow

this is my plant about a day before it started die-ing

miracle grow is not a good soil to start off with what lights are you using
[SIZE=+0]have you wartered the plants have you a ph tester & moisture meter[/SIZE]
seedlings dont want a soil with nutrients in it yours has the ph will be out of wak probly about 5 when you want it between 6 & 7 when you water miracle grow nutes are released from the soil the plant needs to be at least 3 weeks old before you give them nutrients change your soil & repot

confused

miracle grow= shit

keep your soil on the dry side. then mist ur seedlings 2 to 3 times a day lightly and dont water. give them nothing but the mist. they should come back a bit. then trans plant into differnt soil. ive noticed that the seedlings like it kinda dry any how. i fert my seedlings and get great results in my seedlings. but i also have a way that i use to get them to accept the nutes early on.
but in this case i agree with welsh .