Most grow-light guides are a list of Amazon links with the word "full spectrum" repeated. That is useless. A light either delivers the photons your plant can use or it does not, and you can tell from three numbers. Here is what I would actually buy.

The three numbers that matter

  1. PPFD (µmol/m²/s) — how many usable light particles hit the leaf. A low-light plant wants ~50–150; a succulent or herb wants 200–400. Below 50, nothing grows; it just survives.
  2. Spectrum — "full spectrum" white LEDs in the 4000–6500K range are fine for foliage. You do not need purple "blurple" lights; they look cool and photograph badly.
  3. Coverage at height — a panel rated 300 µmol at 15 cm might deliver 80 at 45 cm. Hang height decides everything.

The basics of grow lights cover setup; this is the buying shortlist.

What I would buy, by situation

  • One shelf, a few plants: a 20–40 W white LED bar with a timer. Look for a listed PPFD or a honest "equivalent to a bright window" claim. ~\$25–45.
  • A 60–120 cm plant shelf: a panel or two bars at 20–30 cm above the canopy, 12–14 hours a day. ~\$50–90.
  • Seedlings / herbs / hydroponic greens: a higher-PPFD bar (~200+ at the canopy). ~\$60–120.
  • Avoid no-name "1000W" blurple panels that draw 20 W and list no PPFD. They are a night-light with a fan.

Timers are not optional

Plants need a day length. A cheap mechanical or smart timer on a 12–14 hour cycle beats a fancy light left on a switch you forget. I have killed more plants by forgetting to turn a light off than by owning a weak one.

Using it without cooking the plant

Start at the maker's max height, watch for sunburn-like scabs on new growth, and raise the light if you see them. More light is not automatically better once you pass what the species wants.

Buy on PPFD and coverage at height, not on watts or color. A \$40 white LED bar on a timer grows more than a \$120 unnamed panel you cannot aim. Start with one shelf light and measure results before you fill the room.