Ph+ up, Ph- Grow, Ph- Bloom are concentrated agents to reduce or to increase, the acidity of the nutrient solution. With the right degree of Ph the plants are able to absorb the maximum amount of nutrients contained in the watering. For Ph adjusters during the growth period, use the Ph- Grow adjuster and during the bloom period the Ph-Bloom adjuster. Ph range recommended 5.8 – 6.5 Available packages: 500 ml, 1 ltr. Checking Ph: When you are growing hydroponically checking and adjusting Ph is a simple matter. It can be a bit more complicated when growing organically or in soil. There are several ways to check the pH of the nutrient solution in your hydroponic system. The easy way to check Ph is to use the digital meters. The most popular type of Ph meter for the hobby gardener is the digital pen. You simply dip the electrode into the nutrient solution for a few moments and the pH value is displayed on an LCD screen. The Ph meters are very accurate (when properly calibrated) and fast. They need to cared for properly however, or they will quit working. The glass bulb electrode must be kept clean and some are required to be wet at all times. The pH meters are actually very sensitive volt meters and are susceptible to problems with the electrode. Many of the Ph meters on the market have AutomaticTemperature Compensation (ATC), which corrects the reading with respect to temperature. On meters without ATC the Ph should be checked at the same time of day each time in order to minimize any temperature related fluctuations. The Ph meters usually need to be calibrated frequently, as the meters can drift and to insure accuracy you must check calibration often. With most pens, the tip needs to be stored in an electrode storage solution or in a buffer solution and should never be allowed to dry out.