Sick Plant. Nitrogen Toxicity? - Trying to Diagnose

OK. You've got two problems here. 1. You're watering way too much. These things need a defined wet/dry cycle as they grow so you always want to let them dry out until the pot feels the way it did when you loaded it with dry soil. Let them dry out as much as you can before you water. It may sound cruel and unnatural, but it's the way they like it best. Allowing the roots to sit around in constant moisture is no good and will end up causing you issues...which is what I think you're seeing here. It's either that or the very beginning of pH issues. 2. pH: You've got to have way to monitor and adjust the pH of any liquids going into your plants (water/feed solution) to a range of 6.3 to 6.7 or the roots of your plant will lock up and the plant can't take in nutrition. You have a couple of options. The cheapest is the pH drops kit. It's around $10 or so and you use a color chart to determine whether you're in the proper range or not. I didn't have great success with those and went to a pH tester. However, be warned...don't waste your money on one of those unless you can afford to buy one that is of decent quality...which is going to cost you $60+. They actually sell a water pH tester that ISN'T waterproof....DUH. LOL Avoid cheap, cheap, cheap or you'll just end up buying it twice. I ordered a new BlueLab today and it ended up being about $79, but they are the Cadillac of testers and you can count on their readings being right.

Back off the watering and let those pots dry out. You should be just fine on light to carry you through the veg stage. Overall, your plants look really good and if you'll fix these two things, you should be good to go. They're really just now getting to the point where you might need some nutes. Nutes aren't supposed to be given until the plant has had the chance to use up what came naturally in the soil mix you're using. Then when you do start them, start at less than half the recommended dose by the manufacturer. Of course, they want you to use a ton of the stuff so you have to run back and buy more, but if you use a good soil mix and understand how to pot your plants up in size as they grow, you don't need to pour a ton of chemicals into your plants unless you just want to. Something else you might think about buying is a ppm tester. These tell you how weak or strong your nute mix is and helps you avoid burning your plants because you've mixed it too strong. There is a range for plants during veg stage and as long as you stay within this range, your plants don't fry. These are really cheap and I think I gave around $15 for the one I'm using right now.

I also would suggest you get on the new grower threads here on the forum and do a lot of reading. Pretty much everything one would ever need to know about the basics of indoor growing is logged there. Information is definitely your friend and it's a lot less frustrating to avoid silly mistakes and setbacks when you can. That comes with knowledge.

Good luck! Hope all goes well. TWW