Check the winners The Grow Awards 2026 🏆
Start My Diary
Start My Diary
Log In
Start My Diary
Home
Diaries
Strains
Shorts
Questions
Contests
Growers
Seeds
Breeders
Nutrients
Equipment
Blog
English
Log In
Sign Up
Following
Follow
Brands
&
Growers
to get updates
Back to Grow Questions
2 bulbs, 1 ballast
sativaman
started grow question 4y ago
Does any devices exist to run 2 bulbs alternatively (like two 12 hrs cycles, one On, the other Off) out of one ballast ?
Open
Setup. Lighting
1 like
Answer
Med_in_Tropic
answered grow question 4y ago
It is possible to rig two timers in parallel with one ballast. Then you can program varying intensity to simulate natural day light with weaker mornings, intense mid-days, and ramping down evenings.
likes
Complain
Similar Grow Questions
Solved
smokinchicken_420
Duda sobre HPS y HQI en espacio pequeño y de madera
Hola amigos, soy nuevo en esta historia de cultivo. Tengo un espacio así: Altura - 1,60cm; Profundidad - 0,45cm; Largura - 0,48cm. Eso es una parte interna del armario de mi cuarto, asi que es de madera. Yo puedo hacer un esquema de lampara HPS y HQI en este espacio? Y el calor?
Setup. Lighting
5y ago
1
Solved
GoodVibeSpreader
Light and Tent, Indoor Grow ?
Hi people, One of my friend planned to grow indoor, he has the perfect room for it but since he's starting and we're growing cannabis on a budget I wonder what light and tent should we start with (for everything else i can help him since I already grown weed outdoor) Thanks !
Setup. Lighting
Setup. Ventilation
5y ago
1
1
Solved
88kasanova
GTMAR 1000watt full spectrum light
I bought a gtmar full spectrum 1000 watt light off amazon, does it really put off 1000watts?? My 4 plants look great except I can tell that some of the under foliage isn’t quite getting enough light, I’m doing some LST.
Week 5
Setup. Lighting
6y ago
2
5
Solved
Growladyeastmidlands
What lights best to flower mars hydro 1600w or hps 600w
Setup. Lighting
5y ago
2
4
Solved
GermanGrows
Panels vs beams
Why is the flowering footprint on a spider farmer sf-4000 5x5 but the Mars fc-4800 is only 3x3 flower with more watts?
Setup. Lighting
5y ago
1
5
Solved
hannabis420
Slow indoor seedling growth
4 days since sprout, issues with light timer, seedlings ended up getting 48 hrs of light after they sprouted, and this AM I found that the timer did not turn the light back on so it got 11 hours of dark last night instead of 6. Could this be detrimental to seedling?
Setup. Strain - Autoflowering
Setup. Lighting
Setup. Seedling
6y ago
1
1
Solved
torgul2000
Led light dangers on the skin
What about arms protection under les lights ? I wear special glasses but as I need to manipulate plants should Onwear long sleeves shirts ? What about that kind of light on the skin? I use 600W dimmable lights Thanks growers
Setup. Lighting
3y ago
5
5
Solved
Macx39
Starter kits!
What can I expect from a 600w starter led, I know they're not meant to be great, but of 2 plants in 1.2 x 1.2 x 2m tent, fan kit, filter, etc. I know it won't great an there loads of other factors but say its a good grow, goes well what can you expect with these of good plant.
Setup. Lighting
4y ago
4
7
Solved
FrankieBones
Light Distance - 3 plants are taller than the others...
Hi all. So I have 6 plants with a 400w HID. 3 of them are about 10-15CM taller than the others. My light is currently about 45CM from the top of the tallest one. Would this affect the shorter plants negatively? Should I raise them to the same level and up the light to 60CM rather
Week 5
Setup. Lighting
6y ago
2
3
Solved
ihatemycat
UV led strip
Has anyone tried or knows if there are any benefits to adding a UVA/UVB led strip? I currently have a 18w strip on one side of the growbox as a test, the specifications should be as follows: http://www.ledlightinghut.com/files/365nm%20UV%20SMD5050%20LED%20datasheet.pdf
Setup. Lighting
5y ago
1
4
Solved
Fusion
LEDs
Please help me understand LEDs as mains. Same amount of money I can run double the plants and produce larger sticky buds with hps/mhl combo. I was always under impression LEDS are a just a better florescent.
Setup. Lighting
6y ago
4
6
Solved
Cdric69738276
Future panneaux led
Salut passionné de jardinage,je suis en pleine réflexion sur mon futur achat panneaux led. Entre le FCE 3000 Mars hydro et spider farmer SF 4000 .... Tout en sachant que j'ai une box 80×80. Si quelqu'un peut me dire lequel conviendrait le mieux s'il vous plaît. Cordialement. 🌱
Setup. Lighting
4y ago
3
6
Solved
2x2growing
Light burn or nutrient burn?
Hey guys. The tips of my leaves are starting to turn yellow and I’m wondering if this is a nutrient burn or light burn? I lowered my ppm feeding to about 250 a few days ago and am growing in ocean forest fox farm soil. And the light is an optic 2 running just the cobs at 24”.
Setup. Lighting
6y ago
2
1
Solved
Theia
Autos and light schedules
Last night my light timer broke. How sensitive are autos to their light schedule being messed with? i was on a 16/8 for the lsat few weeks. Last night my timer broke and i did not realise until midday. Now shes been in the dark for nearly 12 hrs!! Should i expect some issues ?
Week 9
Setup. Lighting
6y ago
3
3
Solved
tricombo420
HPS
Olá, na primeira semana das minhas sementes a que distância devo ter a minha luz ? HPS 400w 120x120x200 Obrigado
Setup. Lighting
Germination. Other
5y ago
3
4
Solved
Hisknibbs935
Hello,I'm gonna be running a test 6400k cfl vs sunmaster hps,been reading and reading and blue light crops up alot for veg so,I'm gonna grow one under the cfl one under the hps and one in the middle of the 2.will it shock my plant putting light schedule to 24 and adding the blue?
Week 2
Setup. Lighting
6y ago
2
2
Solved
KaptainKronicX
Xs1500 in 3×2?
Is my light strong enough for flower? 36" x 20" x 63" tent with a viparspectra xs1500. Want to Scrog to fill out the whole tent by and into flower (refer to first grow). Anyone that's used the viparspectra line advise plz 🙏
Setup. Lighting
5y ago
3
4
Solved
Kershaw1231
Is this OK?
Hi my tent arrived yesterday so I put my 6 auto plants in there my auto nl and 5 other auto seedlings what I need to start diary on them but I run light 18/6 schedule on at 6 am of at 12 am but I've changed today to of at 1pm on at 7 pm is that OK? ?
Setup. Strain - Autoflowering
Setup. Lighting
Setup. Seedling
5y ago
4
Solved
RealTrees_uk
Noob question
I have 2 mars hydro ts1000 leds as my normal set up but I have also put back up my 600w dual spectrum HPS on an angle running at 4 to give extra light coverage, just wanted to know if there was any point in doing this as I’m not sure quite new to growing thanks in advance 💯✌️
Setup. Lighting
6y ago
2
2
Solved
potfromgreece
Led bulb 54watt in total
Is 6x9w led bulbs(2700k from Leroy Merlin) is enough to grow a plant? 54w in total.
Setup. Lighting
6y ago
4