Why do you think it's too much calcium? The purpling symptoms sound more like phosphorus deficiency. Check out the link below, but here's the excerpt on phosphorus:

"Phosphorus - P - Deficiency
Lower leaves and stems [I've seen it on middle and upper-middle leaves, too.]

"First sign of deficiency is stunted plant growth, and leaves become darker green. Then, lower leaves and stems may develop red or purple coloration. In worst cases, lower leaf chlorosis [yellowing] and necrosis [death] occurs. Slight phosphorus deficiency is used in plug production to reduce size and darken leaves. In most cases P, deficiency is not common."

When they say that P deficiency is not common, they are talking about in crop soils, not potted plants that depend on you for their P. And even in plain old dirt, you can see P deficiency fairly often, at least I have. I think that sometimes, it indicates that you've given the plant plenty of nitrogen and/or potassium, and all that rank growth makes it P-starved.

Pics would help nail it down. What grow media and fertilizer have you used?

Deficiency and Toxicity Symptoms
ohkelly Reviewed by ohkelly on . to much calcium in the water Can anyone tell me a solution to my problem...i have to much calcium in the water here in my well for my plants. i have narrowed down the problem to this.....to much calcium makes the branch to the leaves purple and the main salk also has purple in it..and the leaves are turning light purple...can someone tell me how i can treat my water to make this excess of calcium go away? Rating: 5