Tight muscles is not always calcium. It's more often potassium, magnesium, vitamin D and if the nerves are involved Lecithin. If you're taking lecithin and the cleansing drink 2x a day, then the best supplement would be CalMagFizz, or simply taking in 1 level teaspoon of Epsom Salts in 12 ounces of water.
Best sources of calcium are dark green leafy veggies. That's one of the reasons I juice parsley as often as possible. You can also munch on cilantro, add kale to your soups, sautee spinach.