I would bet on it. If one goes to heavy on Mg (which is a real common problem), soils close up. Then the water sits as do nutrients, often causing burns when they shouldn't. Realize that calcium uptake happens only at the tip of the root, in exchange for aminoacids and such, when there is too much water, the plants acids are diluted. You can have Ca deficiency even in Ca rich environments for this reason.
Given the size of those containers, the roots on the outside are surely potbound and subject to drying out real quick. Most folks over water and at the same time don't water enough. Sound like a paradigm? It is . How does that work, well, putting on too much water at one time. Then the top soil can dry out while the plant sits in water, losing roots. Or if you are potbound, a light application of water just around the outside margin might help between waterings.
The idea behind watering is simple. Think of a glass of water. You want that glass to be half full before you water again. When it is half full, you cannot water heavily, just a light watering, just to moisten the top soil. Keep an eye on those older leaves, they should stand up. They aren't. The next watering the same, a light watering. When that pot is feeling very light you see a bit of stem sagging, time to water, and water this time until it comes out the bottom. Depending on the situation and evaporation, this might be 2, 3, even 4 light waterings. Watch to see the difference in vigor! You will like it.
With all that said, if you don't have enough Ca, you might not like these results as the salts will bite you hard due to osmotic pressure. And one more point, N is the enemy of Ca. They are antagonistic. And Ca is the toughest element and the most critical to get into your plant.
I am posting an article for you to read. Print it out. Then go pencil in the THC levels from table 6 into table 3. What you will see will make your jaw drop. Note the highest Ca in the leaves has the highest THC by 2 and 3 times!
