First Grow: Living the Dream

@ajr0327 by all means trim any leaves that are making contact with the soil as it could lead to problems from infections also you remove any leaves or lower branches that will not get adequate light to grow anything worthwile . I'm not a fan of defoliation for the sake of aesthetics or fancy techniques and I only do it when its for my benefit or the plants health requires it. You see the leaves are like "fuel" for the plant they create cholryphyl which is then converted to energy so that the plant can grow. If too many leaves are removed the plant will suffer too many growers solely rely on the nutrients they feed their plants forgetting that without the adequate foliage those nutrients will remain in the soil rather than be taken up and converted to energy .

You grow in coco,leaves showing absolute magnesium deficiency,my bet is you didn't feed each time you water up until here.In coco,try to feed each watering.its not like soil,it needs to be fertilized any time you water it.especially calcium and magnesium are lacking.burns at leaf edges are caused by skipping feeding and giving only water.they surely had some amount of exces nutrients and when you stop adding nutes to your watering,they tried to absorb excess minerals with that nuteless water,amount of water is not enough for them to absorb completely and this happens.experienced it before,a few times and I'm pretty sure about it.feed each time and add some magnesium.if you see serious nute burn on your leaves,flush once only,then add some nuted water again.