I don't know whats eating your buds, but I think your nute-lock problem is actually related to using the no pest strip in close proximity to your plants. my buddy put one in his stealth grow and within a week half the plants were dead. At first it looked like nute burn, and then nute lock and then BAM dead. He was able to rescue 2 big ones by removing the no pest strip, washing the walls, ceiling, and floor, and flushing, and spraying the plants with water. I hope this isn't whats going on with you... good luck!