Dr. Tank Substrate Root Fertilizer Tabs is a all-in-one formula for aquatic plants. It provides both macro and micro nutrients for plants. Contains:  30 tablets HOW TO USE? Embed root tabs near the root of plants that uptake nutrients from subtrate in higher rates such as Cryptocorynes. Root tab can also be used to target specific plants showing nutrient deficiency. Root tabs must be used in addition to regular water column and/or substrate fertilization.