What should the pH of the nutrients be?

The nutrients should be kept between pH 5.2 and pH 5.8 with pH 5.5 being optimal.

After mixing your nutes,check the pH with a good pH pen or meter and adjust the pH of the final solution accordingly. Your nutrients should be checked on a daily basis to maintain the proper pH, making adjustments accordingly.

A hydroponic grade pH meter is a MUST in any hydroponic system to accurately measure pH. When pH is too high or too low, some nutrients become unavailable to the plant causing an inability of the plant to uptake the proper nutrients. This will eventually lead to nutrient deficiencys and poor health of the plant. pH must be kept in the acceptable ranges and preferably as close to optimum as you can to ensure proper nutrition and health.

Hydroponic grade pH down and pH up can be bought at any hydroponic supply store and should be used to adjust the nutrient solutions pH. In a pinch, if you are waiting for your bottles of pH up & down and need to correct the pH immediately, you can buy aquarium grade pH up and pH down at your local pet supply store. This will correct your immediate pH problem, but I dont recommend using it on a regular basis. You need to get the proper hydroponic grade pH adjustment fluids.