Did i Burn them With Nuts , Burn Light ,or i dont feed em enough ?

Follow your manufactures lighting guide for appropriate hangheights and dims settings. should not be hurting it. If light is an issue it can bleach the top of the plant and it makes the internod length of the plats very tight. This is the space between branches and leaves. You feeding program should have something like Micro Grow Bloom and you mix them in different ratios. good ones don't need extra CaMg but some of them do. You might need more regular feeding from the Grow part of the feeding program. check out their guides on the website for whoever makes the products. To me that leaf burn is from to much stuff in the medium. Always water to 10-20% runoff to prevent buildup. PH seems on point.

Overwatered. lack of oxygen. is my best guess. Even though I think Oragonoman knows what he's talking about. Theres still the chance with the roots that small I could see how the roots could be drowned out, if not lime left to dry. I do not underestimate the ability of a beginner to overwater a plant. No offense lol.its one of the easiest things to do. Even more when they are small and barely have any roots. There may not be enough light, although they usually stretch like crazy when that's the case. Seedlings sometimes like up to 400 ppfd but usually around 250. Also like mentioned below you need to get them some nitrogen too if you are in pure coco. Coco is a bit unforgiving, especially if not buffered, liked mentioned.

coco is known as a neutral grow medium, but there are cation exchange sites in coco. These sites on the surface of the coco fibers will form bonds with particular nutrient cations. The cation exchange capacity of coco is unlike soil or other grow media. There are far fewer exchanges and the exchange sites will become stable (buffered) once they attach to Ca or Mg. The cation exchange sites in coco naturally come loaded with sodium (Na) and potassium (K) cations. However, the sites have a weak hold on the Na and K cations. In the presence of calcium (Ca) or magnesium (Mg), the sites will release their Na or K cations and lock onto the Ca or Mg. Once the cation exchange sites in coco have locked on to Ca or Mg, they are “buffered” and stay stable. The cation exchange sites in unbuffered coco can pull nearly all the Ca and Mg out of a nutrient solution. If you try to grow cannabis plants in unbuffered coco, they will experience Ca deficiency. This is tough to correct while plants are growing because Cal Mag supplements have a strong impact on electrical conductivity (EC). As a result, the total dose of CalMag that you can provide is limited, even though it all may be going to the coco and none to the plant.

All the things you are giving are supplements, not "food". You will need to give them some "grow" type fertilizer asap, coco has no nutrition in it at all. Start with a weak dose and work your way up as the plants grow. Don't worry about the suggestion that things are too wet, it is almost impossible for coco to be saturated to the point of suffocation.