Crusty leaves on the bottem, curly leaves on the top.

I am a coco grower and you are showing toxicity and deficiency at same time. To me that means you are not getting adequate run off and are not maintaining the coco right. Coco is high irrigation. It is a inert substance of coconut husk. You need lots of run off regularly to grow properly in coco. Your run off ph is very important. Cal mag is also need in coco grows. It is Hydro growing in a Potter or bag. I recommend a good flush with 5.8 ph water. Wash out the salt build up, and correct ph value in coco. I don't run any lower then a 5.8 ph in coco. You can not over water on coco unless you leave it in run off. After flush reapply nutrients. Don't stop your flush till ph and ppm of run off are in a good range. Coco is notorious for a bounce back in ph. You can flush your plant daily and it will actually thrive in coco if you provide right nutrients, and ph value.