Enter your grow space and we'll tell you exactly what wattage you need — plus the best lights for your budget.
Input the length and width of your tent or grow room in feet, metres, or centimetres.
Vegetative growth needs less light than flowering. Full cycle gives you a light that handles both.
We calculate your ideal wattage range and match you with the best lights for that footprint.
For LED grow lights, aim for 25–30 true watts per square foot for vegetative growth and 35–50 watts per square foot for flowering and fruiting. A 4×4 ft tent (16 sq ft) needs roughly 400–500W for veg and up to 700W for heavy flower. Note that these are actual draw watts — not the inflated "equivalent" wattages some manufacturers advertise.
PPFD (Photosynthetic Photon Flux Density) measures how much usable light actually hits your plant canopy per second, measured in µmol/m²/s. Vegetative plants thrive at 400–600 µmol/m²/s. Flowering plants want 600–900 µmol/m²/s, with some strains pushing higher. Watts tell you how much power you're using — PPFD tells you how much light your plants actually receive. Always ask for a PPFD map when buying a grow light.
Both brands ship to Canada and both use Samsung LM301 series diodes in their top-tier lights. Mars Hydro tends to have faster Canadian shipping and more local warehouse stock. Spider Farmer's foldable bar lights are excellent for tents where you need to adjust light height frequently. For most Canadian growers, either brand will outperform cheaper options significantly — the key is choosing the right wattage for your space rather than the brand.
A 300W LED running 18 hours/day costs roughly $22–28/month in Canada at average electricity rates of $0.14/kWh. Rates vary significantly by province — Quebec and BC are among the cheapest in North America (~$0.07–0.09/kWh) while Ontario and Alberta average $0.12–0.17/kWh. Use the calculator above to see your estimated monthly hydro cost based on your light size and province.
The most popular tent sizes for Canadian home growers are 2×2 ft (personal/micro grows), 3×3 ft (2–4 plants), 4×4 ft (4–6 plants, the sweet spot for most home growers), and 4×8 ft (larger yields, two-light setups). A 4×4 tent fits in most closets and spare rooms, runs efficiently on a 400–500W LED, and can produce substantial harvests year-round regardless of the Canadian winter outside.
Everything you need to dial in your indoor grow.