LED vs HPS for a Home Grow: An Honest Comparison
By The Budometry TeamPublished Updated
HPS built the modern indoor grow, but in a bedroom-sized tent the heat math has decided this argument for most people.
Part of our pillar guide: Cannabis Grow Lights: Sizing, Height and Schedules
Heat is the deciding factor
A 600W HPS dumps enough heat into a 4x4 tent that summer becomes unmanageable without serious ventilation or air conditioning. An LED of equivalent output runs meaningfully cooler and moves that load to a heatsink you can vent more easily.
Electricity
Modern LEDs deliver roughly 30-40% more usable light per watt. Over a 12-week grow running 12-18 hours a day, that is a real line item on your power bill.
Upfront cost
HPS is cheaper to buy and more expensive to run, and bulbs degrade and need replacing roughly annually. LED costs more up front and typically pays back within two to three grows.
When HPS still wins
Cold garages and winter grows where the heat is a feature, not a bug, and very tight upfront budgets.
Frequently asked questions
- Does HPS produce better flower?
- Older comparisons favored HPS on density. Modern high-efficacy LEDs with good spectrum and adequate intensity close that gap.
The full guide on this topic
Cannabis Grow Lights: Sizing, Height and Schedules
How to size an LED to your tent, set hanging height by stage, run 18/6 and 12/12 on a timer, and hit the PPFD and DLI numbers that actually grow flower.