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.

For those who do not want to spend money on a lab test, it is advisable to monitor water quality using a nutrient meter. At levels between 200 and 300 PPM it is advisable to use Hard Water Micro, together with Calnesium, to balance out Calcium levels. Any tap water over 350 PPM should only use Hard Water Micro without Calnesium.