Most aquarium plants can absorb nutrients from both the water column and the substrate (e.g., gravel, sand, or aquatic soil), but some species prefer one method over the other. If your plant is a “root feeder” that favours consuming from its roots, then we need to give it a nutrient-rich substrate or ground-based fertilisers called root tabs. For healthy and luscious growth of your aquarium plants, adding root tabs on monthly basis is recommended. Importance of root tabs further increase if you are using an inert substrate like aquarium gravel or sand that lacks any nutrients on its own. Root tabs greatly benefit root feeding plants like Cryptocoryne plants (or crypts), sword plants, bulb plants, carpeting plants, and plants that produce runners. Directions: One root tab for every 5-6 inches is recommended for scarcely planted tank, while for a densely planted aquarium, one root tab for every 4 inches is to be used. Root tabs should be inserted directly underneath or near the roots of your plants. For larger plants like Amazon swords multiple root tabs must be placed in a circle around their root zone.