Euthanasia on these plants?

Well, they are all overfertilized it seems but 1 is still looking ok, the other 2 are not looking good as you can see, the tall and leaf less one has been losing leafs little by little and doesn't seem to be getting better (same as the smallest one) and is already 3 months old without showing any sex, and the other 2 are 2 months old. They are on about 18 hours of light but I'm thinking of swithching to flowering on the healthy looking one. The other 2 I'm not sure if I should keep tring for them to regrow on 18 or if I should just bin them?

http://i743.photobucket.com/albums/x...0/IMG_3401.jpg

http://i743.photobucket.com/albums/x...0/IMG_3403.jpg

http://i743.photobucket.com/albums/x...0/IMG_3399.jpg