Increase transpiration to increase the uptake of calcium. I suggest you get some gypsum pellets and put some in your media to help with the inherent calcium uptake problems under led. I'd run my room hotter if I were you, you want leaf temps over 80 degrees, My plants love a 90 degree room and deficiencies disappeared once the environment is dialed in. These new leds are a lot stronger than most people think, too much light will manifest myriad symptoms and you could be chasing your tail. If the transpiration and leaf temps are not ideal, they won't be able to take the light in and you will stress them. Stress can be slight or extreme, not all deficiencies are from lack of nutes, many are from an overabundance of them. One problem/symptom I see often with led grows is not enough air circulation leading to calcium, and magnesium deficiencies. People blame it on the lights, say they're junk. They almost look hungry when they have all the food and light they need, actually more than they need. Think about your grow like a chain, the weakest link will always hold you back. I gave up calmag, use gypsum and epsom, and my babies thank me for it. Most of the time I see people "fixing" their "calmag deficiency," with calmag, they likely did not "feed the stretch" with grow nutes. I see so many ppl recommend switching to bloom nutes at the flip, and people listening and then wonder why their plants start looking like shit. The calmag likely just gave them the nitrogen they sorely needed. Man I sucked when I started out, I listened to the helpful people here too much. I saw one guy giving great advice and everyone shit on him, his name was uncle ben. I owe that guy a lot of thank yous. I didn't stop listening to people and started listening to the plants like he said, I'd likely still be a shitty grower. Old growers have been down most of these roads, they know tricks and have useful info, don't hesitate to pull up a chair and listen to these people... you might just learn a thing or two. Just remember, less is more. I never, ever, ever, use the recommended amount of nutrients, hardly ever go above 1.0 ec and do just fine. Another tip I can give is I ran my tent fans opposite of what most people recommend, I use the top as air intake and the bottom as exhaust. This helps transpiration immensely and leads to faster growth. Call me crazy but I go for results, not myth. Good luck my friend.