Root Tabs Packed with essential nutrients for your plants.If you are using sand or gravel these little tabs are a must-have for any rooted plant!Very safe for use with any fish or shrimp just push 1-2 tabs into the substrate near the base of the plant and you are ready to see better growth. For heavily planted tanks you can use 1 per 12cm x 12cm area.Replace every 2-3 months in sand or gravel and every 3-4 months in plant substrates.Contents17% nitrogen (N)9% phosphorous pentoxide (P2O5)11% Potassium oxide (K2O)2% Magnesium oxide (MgO)0.01% Boron (B) 0.006% soluble in water0.025% Copper (Cu) 0.017% soluble in water 0.22% Iron (Fe) of which soluble in water, chelated by EDTA 0.033%0.03% Manganese0.01% Molybdenum 0.008% soluble in water0.008% ZincEnjoy!