Planted tanks fail in both directions: a powerful light over undemanding plants grows algae, and a weak light under demanding plants grows disappointment. The way through is to grade your plants by demand first, then buy and set the light for the highest tier you genuinely intend to keep. The three tiers below describe the plant's appetite, not the price of the lamp.
Low Demand: Gentle Light, Slow and Steady
Low-demand plants are the hardy slow growers — the kind that tolerate shade, forgive irregular routines and ask mainly for time. They do well under modest light for a moderate day, and they suffer more from excess than from restraint: blast them with a strong lamp and algae colonises their slow leaves faster than they can replace them. This tier suits a first planted tank and any tank where the fish, not the aquascape, are the point. Because growth is slow, planting densely from the start matters — there is no quick fill-in coming. Root feeding helps the rooted species here, while the water column stays lean.
Medium Demand: A Real Light and a Real Routine
Medium-demand plants — many of the popular stem plants and midground species — want clearly more: a light with genuine reach to the substrate, a consistent photoperiod on a timer, and regular plant food to match the faster growth. This is the tier where routine starts to pay visibly; stems trimmed and replanted thicken the display within weeks. It is also where inconsistency shows fastest, because growth fast enough to impress is fast enough to stall when food or light wavers. Most satisfying home aquascapes live in this tier, demanding enough to look lush, forgiving enough to survive a busy fortnight.
High Demand: Light Is Only One Leg of the Stool
High-demand plants — tight carpets and the vivid red stems — need intense light, but light alone guarantees nothing except algae. At this tier, carbon dioxide injection and a full feeding routine are not upgrades but requirements: the plants can only spend the light if carbon and nutrients arrive in step. Trimming becomes a weekly craft, because fast tops shade slow bottoms ruthlessly. Choose this tier deliberately, knowing it is a commitment to a system, not a lamp. If you are not ready for the gas and the routine, the honest move is to pick medium-demand lookalikes and enjoy a tank that stays balanced.
One Tank, Mixed Plants: Arrange by Appetite
Most real tanks hold a blend, and placement reconciles them. Put the light-hungry species in the open, directly under the lamp's strongest spread; tuck the shade-tolerant ones under driftwood overhangs, behind hardscape and at the dimmer ends of the tank, where they receive exactly the gentler light they prefer. Floating plants are a living dimmer switch — let them thicken over the low-demand corner and thin them over the carpet. Then judge the whole arrangement over a month: leaves reaching and pale means a plant wants more light; algae filming the top leaves of a slow grower means it is getting more than it can use.
That sorting of a plant list into tiers, done before any equipment is chosen, is what saves the money and the algae battles. For a tier you are unsure about, put a follow-up question to KinsLe's Kinny; he answers using the KinsLe Answers library.