Setting Up a Planted Tank

Live plants do more than decorate: they take up nitrate and other nutrients, compete with algae, oxygenate the water and give fish shelter. A well-planted tank is often more stable and easier to keep balanced than a bare one — but plants are living organisms with their own needs.

The three inputs. Plants need light, nutrients and carbon. Adequate aquarium lighting drives photosynthesis; too little starves plants, while too much light without matching nutrients feeds algae. Nutrients come from fish waste, the substrate and, if needed, liquid or root fertilisers. Carbon comes from the water; demanding, fast-growing plants benefit from added CO2, but many hardy species do fine without it.

Start easy. Beginners should choose low-light, hardy plants such as Java fern, Anubias, Java moss and Amazon sword. Several of these attach to wood or rock rather than needing to be planted in substrate, and they tolerate a wide range of conditions. Avoid demanding "high-tech" carpeting plants until you have experience — they usually need strong light and CO2 and will melt without them.

Balance beats intensity. The common failure is imbalance: strong light with no CO2 or nutrients grows algae, not plants. Match light duration (a timer set to a moderate photoperiod of around eight hours), keep nutrients modest, and let the tank settle over weeks rather than expecting instant results. Some initial melting of newly bought plants is normal as they convert from their emersed nursery form to underwater growth; do not throw them out at the first sign of it. A gently planted, low-tech tank with hardy species is both beautiful and forgiving, and it directly benefits the fish: plants shelter shy species, dampen algae by out-competing it for nutrients, and help keep the water clean and stable. Group plants by height — low foreground species at the front, taller stems at the back — so fish have both open swimming space and cover.