Help with Bubbleponics

Okay so basically I need some help. I am about 3 1/2 weeks into my grow and on the end of my leafs I keep getting browning and dying leaves. I am using foxfarm nutes and I have just cut back the recommended dose for fear of nute burn but it doesn't seem to be doing much. pH is between 5.5 and 6.3, and I am just looking for some helpful advice not criticism for not reading or something like a lot people say. So if you could help me I welcome all your advice. This is the issue ----->

I bet this is your first hydro grow.

Those are very very healthy looking plants you have there and nothing is wrong witht them. It is very apparant that you've done your homework and studying.

Every leaf has a coresponding root in the tank. Pull off a root near the top or enr the cup, and a leaf will yellow on the sides, or ont he tip, or the leaf will curl, etc.
Going in and of the tank taking water samples we will accidently damage a root and we will see it's affect on a leaf.

Soon, you will experience a lot of drying, crisping and falling off of the bottom 1/5 of the plant, againt aht is OK, and normal too.

Those pics look fine to me. Pat yourself on the back.

I agree! You are doing excellent on your first grow. You will learn how to grow even better the next grow. I'm on my 6th and in my first try I killed all but one plant but I did learn how to grow and what not to do. You are ahead of me!

Looks like "overwatering" to me. LOL! Just kidding! I use FoxFarm nutes too and I had the same thing happen. Like Crazy and Roseman say. . . it's normal. I know that I got a little overzealous with my nutrient schedule there for a bit because the plants seemed to be able to take anything. Then they finally gave me signs of nute burn. Just make sure you are following the nute schedule per their measurements. Also, if you haven't decided to use the FoxFarm Water Solubles, I'd highly suggest it. My colas are doing great! Much better than my last grow did without them. Open Sesame, Beastie Bloomz, and Cha Ching really get them going. I think you can get them from Amazon.com. I know I got a bottle of my FF Big Bloom from them.