Lighting — LED Grow Lights

This is the largest group in Lighting and the hardest to compare within, because nearly every lamp advertises a wattage. Watts tell you what goes in, not what comes out. That sits in a different number, and it is the one to choose on.

Watts are consumption, micromoles per joule are output

A grow light's efficiency is expressed in micromoles per joule: how much usable light a fixture makes per unit of electricity. Fixtures of equal wattage differ considerably in it. Lux Helios puts that figure in the product name and states 2.8 µmol/J across the range. On the other brands it sits on the product page. Compare on that, and use watts for your electricity bill.

The main lights

Mars Hydro has the FC EVO and FC-E as folding boards and the TS series as an entry point. AC Infinity supplies the IONFRAME EVO3 to EVO8, from 280 to 730 watts, plus the IONBOARD S22. Lumatek is here with the Zeus Pro 3.1 and ATS Pro, ViparSpectra with the P, the XS and the heavier KS3000 and KS5000, and Spectrabox with the UFO for a small space.

Shape decides the coverage

A board with bars spreads its light across the whole area and can hang closer, which is decisive in a low tent. A compact UFO concentrates more and needs height for an even pool. So choose on the ratio between your floor area and your height: the same wattage in a different shape gives a different spread.

What else is in here

This group collects everything that is LED, and not all of it is a main light. The Cosmorrow bars and the IONBEAM belong under supplemental lighting and hang alongside a main lamp. The IONBEAM Green is work light for the dark period. The VF bar belongs to vertical farming and the Cosmorrow supplies to Power Supplies & Drivers.

For cuttings and young plants

A main light is too strong for a cutting. For those there is the cool fluorescent under Fluorescent and the Cosmorrow in its lower wattages. Do not put a young plant under a heavy board assuming you will raise it: that is what makes it stretch.

Frequently asked questions

How many watts do I need for my tent?
That follows from your area and your stage, but look above all at the stated coverage. A lamp rated for your size that scores well on efficiency beats more watts in the wrong shape.

What counts as good efficiency?
Higher is better, and it compounds over thousands of hours. Compare the stated figure between candidates rather than hunting for a threshold.

Can one lamp do both growth and bloom?
With LED, almost always. A full spectrum fixture covers both stages, and dimming follows the stage rather than swapping the lamp.

Why does a board hang closer than a panel?
Because the light is already spread across the surface rather than coming from one point, which gives a flatter pool at short range.