I am afraid you have not posted enough information. Besides, such thing are best troubleshoot by simplifying the situation step by step and patiently checking everything. Start with just plain water. Is the color of the indicator without calcium as expected? Does it change after modifying pH with the base? Does it change after adding calcium? Are these changes/lack of changes as expected? If yes: error is somewhere else. If not: this is a hint as to what is going wrong.