You have some tall skinny clones their I'm not sure if they stretched or they were just cloned like that? When your are watering are you lifting the pot to make sure it is dry? The tips could be yellow from a few things, too much water/nutes, too much light 1000w is it mh?, too much heat...do you have a temp/humidity device? Make sure you keep the temp around 75f if you can with that 1000watter. Other than the yellow tips they seem okay, just make sure your not over watering. Its hard not to do when you first start out because you see something wrong and think it needs more water/nutrients, when it usually something else like ph issues or lockout. Do you adjust your ph when you add your ferts? If not I would definetly get a liquid ph tester stat until you can find a good digital one. I tds/ph pen would be best so you can also know exactly how much nutrients your feeding them. Good luck:greenthumb: