GB Series LED Grow Bulb by Treegers — Full-Spectrum E27 Grow Light (15W or 30W)
GB15W (15W)
Pairs well with
Not every plant needs a six-bar fixture. The Treegers GB Series LED Grow Bulbs are built for the setups that don't — herb gardens on a windowsill, a propagation shelf, a small soil pot under a standard lamp fitting, a veggie seedling rack. They screw into any E27 socket (the standard household screw-in fitting found in most Australian lamps and light fittings), run 4800K full-spectrum COB light at 2.2 μmol/J efficiency, and carry a 5-year warranty that most expensive fixtures can't match. The GB15W handles compact low-light setups; the GB30W doubles the output for anything that needs a bit more push.
Choose Your Model
15W / 1600 lm / 30 μmol/s PPF
Best for: herbs, seedlings, small propagation setups, low-light ornamentals, supplementary light under shelving
30W / 3200 lm / 60 μmol/s PPF
Best for: leafy greens, fruiting plants, small hydroponic systems, compact grow tents, year-round indoor growing
Tech Specs — Side by Side
| Specification | GB15W | GB30W |
|---|---|---|
| Product Code | TGB0001 | TGB0002 |
| EAN / GTIN | 9309001188269 | 9309001188276 |
| Power Draw | 15W ±5% | 30W ±5% |
| PPF Output | 30 μmol/s | 60 μmol/s |
| PPE (COB) | 2.2 μmol/J | 2.2 μmol/J |
| Lumen Output | 1600 lm | 3200 lm |
| Lamp Housing | PAR20 | PAR38 |
| Lamp Base | E27 (standard household screw fitting) | E27 (standard household screw fitting) |
| Bulb Dimensions | 64 x 94mm | 120 x 135mm |
| Bulb Weight | 150g | 450g |
| CCT / Spectrum | 4800K Full-Spectrum GB4800K | 4800K Full-Spectrum GB4800K |
| CRI | 92+ Ra | 90+ Ra |
| Light Distribution | 60° | 60° |
| Input Voltage | 100–240V / 40–50Hz | 100–240V / 40–50Hz |
| Ingress Protection | IP44 | IP44 |
| Thermal Management | Passive Cooling | Passive Cooling |
| Lifetime | 50,000+ hours | 50,000+ hours |
| Energy Class | ERP A++ | ERP A++ |
| Certifications | CE, UKCA, SAA, C-TICK, RCM | CE, UKCA, SAA, C-TICK, RCM |
| Warranty | 5 Years | 5 Years |
What's in the Box
- The GB15W suits compact setups where you need light in a small footprint — a single herb pot, a propagation tray, a small shelf with one or two plants. It delivers 30 μmol/s in a PAR20 body that fits neatly into desk lamps and reflector fittings.
- The GB30W doubles the output to 60 μmol/s in a larger PAR38 body — better for a shelf of leafy greens, a small fruiting plant, or anywhere you need more photons per square metre.
- Neither bulb is a substitute for a dedicated GL-series fixture in a proper grow tent. They are supplementary and standalone lights for smaller, lower-demand setups.
- The 60° beam angle concentrates light directly below — position the bulb directly above the plant canopy for the most efficient delivery, not off to the side.
- Both bulbs are compatible with timers and smart plugs for automated photoperiod management without needing a Growcast or dimmer controller.
How to Get the Best From Your GB Series Bulb
Pairs Well With
The GB15W at 30–40cm above a propagation tray delivers gentle, spectrum-correct light for clones and seedlings getting their start.
Grow Systems and ContainersCompact hydroponic systems and soil setups benefit from a single GB30W overhead for herbs, leafy greens, and small fruiting plants.
Hydroponic NutrientsFeed your plants properly even under a simple bulb setup — full-spectrum light means full nutritional demand.
Treegers GL420W LED FixtureOutgrowing your bulb setup? The GL420W is the natural step up to a dedicated fixture for a full 1.2 x 1.2m tent.
SubstratesGood light and good substrate go hand in hand. Pair your grow bulb with a quality coco or soil blend for the best results from a simple setup.
Environment ControllersEven simple setups benefit from environmental awareness. Monitor temperature and humidity to keep your plants in their ideal range.
Frequently Asked Questions
Will these bulbs fit my existing lamp?
Yes — E27 is the standard large screw-in fitting used in most Australian lamps and ceiling fittings. If your lamp takes a normal household bulb, it will take this one. The GB15W (PAR20) is compact and fits most desk lamps and pendant lights. The GB30W (PAR38) is physically larger — check that your lamp shade or fitting has enough internal clearance for a 120 x 135mm bulb before ordering.
Can I use these bulbs in a grow tent?
Yes, for small tents up to roughly 40 x 40cm footprint. For anything larger, a dedicated Treegers GL-series fixture will provide significantly better canopy coverage and uniformity. The GB Series bulbs are at their best in non-tent setups — shelving, lamp stands, and supplementary lighting — rather than as primary fixtures in a full tent environment.
Are these bulbs dimmable?
No — the GB Series LED grow bulbs are not dimmable. They run at full output when powered. If you need adjustable intensity, a dedicated GL-series fixture with a Treegers T Dimmer or Growcast is the right setup.
What plants are these bulbs suited to?
Both bulbs work across a wide range of plant types — herbs, leafy greens, seedlings, ornamentals, and fruiting plants like tomatoes, cucumbers, and peppers. The 4800K full-spectrum output supports all growth stages. The GB15W is better for low-light and compact plants; the GB30W handles higher-demand crops more effectively.
Can I run these bulbs continuously for 24 hours?
Yes — the passive cooling design and rated 50,000+ hour lifespan mean the bulbs can run extended hours without heat or reliability concerns. That said, most plants benefit from a dark period. Running lights 24/7 is generally not recommended for plant health except in very early seedling stages.
Why does the GB30W have a lower CRI (90+) than the GB15W (92+)?
Both bulbs use the same 4800K Full-Spectrum GB4800K platform. The difference is minor — CRI 92+ vs CRI 90+ — and has no meaningful impact on plant growth. Both ratings are excellent for horticultural applications and represent high colour accuracy well above the threshold needed for accurate plant response across all growth stages.
Full-Spectrum Light. Any Household Lamp Socket.
5-year warranty. 50,000+ hour lifespan. Screws into any standard E27 fitting. Pick your wattage and go.