....hey Mate'-- For sure, you had chewing bug damage, caterpillars or grasshoppers likely,... the edge burn might be both over fert'ing, and if you didn't rinse the hell out of those bricks, you might have excess K and Na (bad!) in there, which will make symptoms worse,... I understand using Ca-mg solution during the coco rinse process helps a lot, since these ions help force the displacement of the K and Na, well beyond what water alone will do, even RO/DI,....