Ok guys I have been growing for a couple of years and have had great success but for this grow I started using a new nutrient and I am having all kinds of issues. PLEASE TELL ME WHAT IS WRONG.

History- For the past two years I have been flooding every other 15 min. Never a problem. Always had great buds.

Plants- They look weak and droopy! I thought it was the amount of nutrients I was putting in so I cut it in half. I also changed the flooding to a few times a day but then I got scared that they were not getting enough water so I switched it back to every other 15 min. The light is the correct distance. Maybe 1 and half feet away from the plants. I am pretty sure my PH tester is working. Had some issues with it but its better.
After two weeks of the grow cycle I should be seeing healthy looking plants with big fan leafs and green foliage. Instead I see plants that are sad looking. PLEASE HELP!!!! SHOULD I GO BACK TO THE NUTRIENT THAT WORKED?