Hi. Until now I've kept my grows pretty basic. I use a 400wt hortilux blue for veg and a 600wt hortilux super hps for flowering. I've been curious to test out supplemental additions of some uv light using the power veg t5 bulbs (that I already have) in two 4 bulb bad boy fixture . My question is how do I incorporate these In flowering? At what week in the flowering cycle? How many weeks in the flowering cycle do i use them? How long per day light cycle during of a 12 hour cycle? Do I use all power veg bulbs in the fixtures or blend in t5 flowering bulbs? How far from the canopy should the fixture be kept? Sorry for all the questions. Any input would be much appreciated. Thanks
Supplemental Uv during flowering
- Thread starter unklemike
- Start date
I am not familiar with the power veg bulbs. How much UVA and UVB do they emit?
If UV is to be used it should be started early so the plant is ready for the UV when flowering, avoiding some of the stress a new spectrum would cause. A single 3% UVB bird bulb mixed in with seven regular bulbs is plenty for veg and can be left on for the full cycle, keeping it simple.
The flowering plant will like a 5% UVB bulb for the four hour noon period. A single bulb 5% UVB T5 on its own timer, or a 10% UVB T8 single on its own timer are enough. An inexpensive two bulb T8 shop light can be used with a regular grow bulb filling the second slot.
The bird and lizard UVB bulbs have at least twice as much UVA as UVB, some brands have triple. so a little bit goes a long ways.
Four hours at noon works well with most plants. Sativa's use more UV, Indica's use less. Too much harms fan leaves and stunts growth. Hybrids, which most plants are, can react either way, some do not like any UVB.
A handheld UVB meter costs about $200 USD, and is a good investment if using UV in the garden. UVB is invisible and damaging in small doses, it is best to have good numbers from an objective source.
Blacklight UVA bulbs are safe but only do half the work, a small amount (1/2 of 1%) of UVB does the other half. UVA can be up to 5%.
Just as some strains do not like UVB, other strains ignore it completely. Try several strains.
If UV is to be used it should be started early so the plant is ready for the UV when flowering, avoiding some of the stress a new spectrum would cause. A single 3% UVB bird bulb mixed in with seven regular bulbs is plenty for veg and can be left on for the full cycle, keeping it simple.
The flowering plant will like a 5% UVB bulb for the four hour noon period. A single bulb 5% UVB T5 on its own timer, or a 10% UVB T8 single on its own timer are enough. An inexpensive two bulb T8 shop light can be used with a regular grow bulb filling the second slot.
The bird and lizard UVB bulbs have at least twice as much UVA as UVB, some brands have triple. so a little bit goes a long ways.
Four hours at noon works well with most plants. Sativa's use more UV, Indica's use less. Too much harms fan leaves and stunts growth. Hybrids, which most plants are, can react either way, some do not like any UVB.
A handheld UVB meter costs about $200 USD, and is a good investment if using UV in the garden. UVB is invisible and damaging in small doses, it is best to have good numbers from an objective source.
Blacklight UVA bulbs are safe but only do half the work, a small amount (1/2 of 1%) of UVB does the other half. UVA can be up to 5%.
Just as some strains do not like UVB, other strains ignore it completely. Try several strains.
uv never did shit in my garden....yeehaw.. I gave my iguana back her light...lol
olekingkole
Active member
Phaeton has it right. I've used T5 Reptile bulbs and had the plants tested, with and without the bulbs. The buds exposed to the T5's had about 10 % more THC. You could see the difference between buds under the microscope. I just used them the last 10 days of flower, 6 hours a day. You have to be careful. The Reptile bulbs really do contain a significant amount of UV, I checked them with a UV meter. As Phaeton suggests, a meter is handy. You need to make sure the UV is going where you intend-it drops off fairly fast with distance, but can still damage plants that aren't hardened off. Riddleme has used these quite a bit. You might check his threads.
olekingkole
Active member
It seems like these mercury vapor lights have a lot going for them in terms of longevity and the amount of light they put out. The only problem I can see is the narrowness of their beam compared to a 48 inch T5 and the sharpness of the drop-off in intensity from the center hotspot of the beam. You might need several at a distance to get an even footprint. Has anyone used them?
