If the quality of your water is poor, it will affect your cannabis by disrupting its biological processes and thus affect your cannabis yield. You should also remember that both indoor and outdoor growth requires good quality water and not extra nutrients as many of the problems that emerge from issues with your water issue can seem similar to the normal problems your plants face. These issues could range from heat stress, fertilization issues, nutrient uptake among others which could only be identified by an experienced grower. As a result, it is important to conduct regular checks on your water quality to be sure if you notice any issues and if such is noticed, all it requires is for you to take a few steps to improve its quality.