Water quality is a big concern when growing hydroponically. To obtain optimum results, it is recommended to use water that contains as little salts as possible. Unfortunately, this is not an option for everyone and some are forced to grow using water with a high mineral content. In most cases, problems in water quality arise from higher rates of Calcium (although it's advisable to do a water test to be certain), and using regular Holland Secret Micro will push Calcium levels too high which increase the chances of having a lockout with the Phosphorus contained in Holland Secret Grow and Bloom.
