What am i doing wrong?

Hey mate ;if you are trying to grow in pure coco ;like nothing added extra in medium ; it does require some micro organisms for plants to establish roots. These micro organisms are present when a root develops and directly depends on it. It just started growing and so it will take a little time to establish those organisms in coco so that roots spread more. Be patient ; starting in coco can be relatively slow ; but once it is 3 weeks old ; it will flourish fast.