10 LBS Masterblend 4-18-38 Hydroponic Fertilizer It is a brand new Masterblend fertilizer that is repackaged into a smaller, more convenient size. Masterblend can be used for hydroponics, aeroponics, and plants in soil. I am positive you will love using Masterblend. I will also include mixing instructions for greens like lettuce and also nutrient hogs like tomatoes so you can make sure you are mixing the right ratio to feed your plants properly. It is the only fertilizer that I use.