First hydro grow. I need input

So this is my first hydro grow using a HPS light its a 425 watt hydro farm setup.

I am using a boto bucket system. got the plans online i included pics of the closet its about 4 1/2 ft. X 2 1/2ft. i have the light about 2 feet away from the plants they are about 4 inches tall.

Ok so now heres my problem one of the plants is streching really bad but the other 3 are doing fine its streching so bad that is falling over . i have 2 different strains growing low ryder #2 and the ultimate. the ultimate is the one thats streching really bad. If anyone has any suggestions or comments or just some helpful tips would be appreciated .

Hi Weedie.
I would say the reason your plant is stretching is because the light is far away ( But you need it far away so it dosnt burn the little babbies ) Iv never heard of the ultimate strain your doing ( is it auto flowering like the lowryder ? ) If it isnt auto like it then thats defo why its strecthing.

Ideally you want CFL's for the 1st few weeks while ther in the seedling stage, Its always worked for me, But diff ppl have diff ways.

Hope this helped.

http://www.thesingleseedcentre.com/products/dutch-passion-the-ultimate

There is a link to the ultimate seed. it is not autoflowering like the lowryder but that shouldnt matter at this early of the stage should it? dont know i have two of the ultimate growing the other is going fine a little streched but nothing too bad.

Thanks for the input though i will keep updating on the plants.