Coco Grow Problems

too early for frequent watering.. That clearly looks like a Nitrogen deficiency. Get your ppms of N up to 120-130, if you have proper soilless/hydro nutes for coco. Your fertilizer should be 100% chelated, 100% soluble and 100% plant ready when dissolved. fertigate every time with a 1.3-1.5EC concentration of well-balanced fertilizer. Always get 10% runoff minimum - religiously! This eliminates concern about buildup in substrate, which means any tox you see in leaves is due to your formula and that only takes an adjustmenet based on observations to avoid it in future. Easier to diagnose problems if you never have to worry about mineral buildup in substrate. Soilless is simple. Don't complicate it. Stick to a wet-dry cycle in vege. Let top layer change color before fertigating again. Feel weight of pot and be consistent at fertigating at that same loss of weight and it will require the same volume of water to achieve 10% runoff minimum. If you want to do frequent fertigations later, you need to have at least 25-33% loss of weight before next fertigation. This requires a properly sized plant to pot size. this depends on what constitutes the substrate -- how much perlitee? total water capacity etc... So, you may not know until you try. Can adjust pot size next time relative to how large you grow you rplants. 2-3x fertigation per day may not need 10% runoff every time, but i'd wager at least 1/day ... i'd do it at the start to make sure substrate is reset to the EC you want at beginning of day... or maybe just less runoff each time... LEss evaporation is occuring between, so less buildup potential in that context, too. Your nutes are all plant available and read to enter roots, if using currect fertilizer for coco coir (or any other soilsless context). plant does not selective grab nutes.. if it is dissolved it enters the plant. buildup can only occur if evaporation is occuring and reducing water volume while dissolved mineral mass stays the same = high concentration over time. The runoff rinses that out and resets it back to "normal" ("normal" may be a bit off from what you mix formula at, but consistency is the key to it wokring well.. it'll be a consistent offset, which is fine to be ignorant of... observe plant, adjust formula.. all the same process of dialing it in) a wet dry cycle early promotes more roots and deeper roots vs superficial roots. So, get them robust before you try to do frequent fertigation ... in fact get a few simlper runs down before trying frequent fertigation.. make sure you know hwo to get a plant seed to harvest with nearly no damage except that caused by inevitable senescence and then move on to more complicated methods of fertigation. Plus, you can form a baseline to compare results.. decide if the hassle is worth it or not while armed with better information to do so.