Only had it for a month or two but this product seems to be ammonium free as they claim. Ammonium is a poison. It spills out of waste water treatment facilities killing off ocean life like phytoplankton and diatoms causing global warming. Also causes ammonia poisoning symptoms in people. Ammonium is not stable and will break down from NH4 to NH3 at random in the soil or in your body. ALWAYS DUMP USED HYDROPONIC SOLUTION INTO THE SOIL NOT THE DRAIN SAVE OUR OCEANS