Help please leaves look sick!!!!!!

is 1 sunlite 42w 120v Fluorescent lightbulb enough light for my 3 plants they are all about 4 weeks old i bought them about 3 days ago i had them in light on 24 hours a day 12in above plants till an hour ago i turned them off because my leaves are turning yellow and crispy im worried that the will die any tips or advise please!!! has to be someone out there

You should be running them 18/6 light not 24. 24 is only for germ stage.

42w is way too little. Hows the weather? Giving it sunlight would be much better than 42w

it will grow under that light. But you'll get wispy shitty buds. I'd go with a bunch of CFLs before I did one 42w light. The 24 vs 18/6 debate goes on and on. Personally I've done both and had success. In my setup 18/6 is much better for my power bill. But I do believe they veg slightly faster under 24/7.

how many light bulbs do you recommend me to use? any brand of lightbulb that would be good for my plants