Sylvania - SHP-TS 600W Growlux

This 600 watt Sylvania SHP-TS Grolux gives 90,000 lumen at 2050 kelvin, with an E40 cap and a nominal life of 26,000 hours.

Hanging height: where light burn comes from

At 600 watts of sodium the distance to your canopy stops being a detail. This lamp makes a great deal of light and a great deal of heat, and those two together are why hanging it too low produces visible damage.

What growers call light burn is usually a combination. The top leaves receive more light than they can process and bleach, while radiant heat dries those same leaves faster than the plant can move water up to them. The picture is familiar: yellowed or bleached tops directly beneath the lamp while foliage ten centimetres lower looks fine. On an HID lamp the heat is more often the culprit than the light.

The practical test costs nothing. Hold your hand at canopy height, back of the hand toward the lamp, and count slowly to thirty. If that is uncomfortable, it is too much for your crop as well. If the lamp rises with the plant, check again every week, because a growing plant closes the gap without you doing anything.

Two things widen the margin: ratchet hangers that let you adjust height under control, and decent air movement across the tops, since still warm air trapped under a reflector is exactly where this goes wrong.

Technical Specifications:

• Model: a0123
• Power: 600 W
• Type: high pressure sodium with Gro-Lux spectrum
• Colour temperature: 2050 K
• Luminous flux: 90,000 lumen
• Cap: E40
• Life expectancy: nominally 26,000 hours
• Ballast: 600 W required, not included

Frequently asked questions

How high should this lamp hang?
There is no fixed figure. Use the hand test at canopy height and adjust weekly as the crop grows.

Is bleaching light or heat?
On HID usually heat, or the two together. Raise the lamp and get air moving across the tops.

Why only the tops?
They sit closest to the lamp. Foliage ten centimetres lower gets noticeably less light and heat.

Does more extraction help?
It removes heat from the room. For the tops themselves, air movement across the canopy helps most.