Lighting — For 120x120

A square metre and a half is what manufacturers aim their flagship models at, and it is also where the two routes cross over. A 600 watt discharge lamp that was generous over one square metre has become lean here, while the heavy LED fixtures are tuned to exactly this area.

Where the ratings sit

The Lumatek Zeus 465W Pro 3.1 states 120x120 explicitly. The ViparSpectra KS5000 at 500 watts states 100x100 and 120x120 and so sits at the top of its range here. From Mars Hydro there are the FC-6500 EVO and FC-E6500 from the bar series plus the TS-3000 as a panel, and from AC Infinity the IONFRAME EVO6 at 500 watts.

Why 600 watts of HPS behaves differently here

The same lamp that gave ample light over one square metre now has fifty percent more area to serve. Fertraso and Sylvania both supply 600 watts, and Fertraso the HPIT metal halide besides, but expect to be at the lean end of what this area wants. In LED the heavy models land exactly right.

Bars against a panel

Over a square metre and a half the shape of the fixture starts to matter more than the wattage. A panel gives a strong core and weaker corners; a bar fixture lays the same power down more evenly and can hang closer besides. In a tent this size with limited height, that is often the deciding property.

The rest of your setup steps up with it

At this area you also move to larger extraction, bigger pots and more than one circulation fan. Count that step in before comparing on lamp price, because the lamp is rarely the most expensive part of the jump.

Frequently asked questions

Is 600 watts of HPS enough for 120x120?
It works, but you are at the lean end of comfortable, and the heat that comes with it has to go somewhere over this area. LED at 450 to 500 watts gives more usable light here.

Bars or panel?
Bars if height is limited or you want the corners filled; a panel if price weighs more than evenness.

Can I hang two smaller lamps?
You can, and it gives a more even spread with the option of dimming half separately. Add the total wattage together.