HELP plant dying need help quick (DWC)

[tetrahydro grower]

This is a sweet tooth plant, and its leaves have been dying and turning different yellow/brownish. This is my first DWC grow, and i didnt relly know what i was doing, and i mainly plsnted it to see if i could actually grow it succesfully, and its been ok until now. Can someone tell me how to fix this problem. The Ph was a little low, so i added baking soda to my water that is going in the rez.

 

[tetrahydro grower]

Please someone help me save herrr

 

[ozzydiodude]

What do the roots look like?

 

[tetrahydro grower]

They are brown.

 

[ozzydiodude]

Are they slimey also if so read this thread
http://www.marijuanapassion.com/forum/showthread.php?t=2177