New to LED

[Greenlivin]

Hey guys, I decided to buy a 600W LED light and need a little help. The light has a veg and bloom switch. I have been using CFLs, and switched to flower today. I have four plants in a 2x4 tent. I’m wondering:

1. Should I use the veg AND bloom setting until buds start to form, and then switch to bloom only?
2. How far above the plants is recommended to keep the light?
3. Should 600w be sufficient for my space and 4 plants? Not aiming for record breaking yields as this is my first time.

Can I expect to see a dramatic difference in growth between the CFLs and LED? Obviously being in flower mode now I understand they will grow much bigger and quicker. Thanks!

[Farmall]

So to start,600w should be quite reasonable for your 4 plants.try to manipulate the plants to gain the most light exposure down through the center of the plant as it grows. The right height is different, and you may find 24” to 30” is about correct but can vary some. If you started with cfl, they can be 2-3”away and be great. Watch out for plants stretching to reach the light and getting tall and spindly...not good. Lower the light a bit or raise the plants. As for the switch, I’m thinking turn them both on but it could also have a very big increase in color spectrum so look first to see what the specs are for the added lighting before throwing both switches on.

[YYCannabis]

UVB isn’t as bad for you as is the spectrum just outside the UVB range. I guess it would be UVC...can’t remember after taking my meds...anyways...yes cellular damage is possible but that depends on how powerful the bulb is, how close to the bulb is your skin/eyes, and how long you stay exposed to the UVB.

UVC would be very different. Very quick cellular damage to skin and eyes...possibly blinding you.

I would follow their recommendation of not risking exposure. 👍

[Farmall]

Thank you YYCannabis. Good to know ... thoroughly convinced I’ve done stuff in life that I should have had this kind of information and subsequently would have avoided. Thank God nothing crazy has happened... and nowadays, I do nothing odd ( except this ) 😁

[YYCannabis]

If people haven’t already seen the vids, Migro on YouTube covered UV bulbs.

https://youtu.be/JPsMH61onMk

[ocgreen]

When it comes to LED, it's important to differentiate between "advertised watts" and actual watts. Companies will often claim LED is a much higher watt than the actual draw from the wall. If you look at specs for your light it should tell you actual.

If it's actual 600W then in my opinion it's too much light for 8 sq ft. I seem to recall that a general rule of thumb is about 40 actual watts per sq ft so you would be ok with around 320W actual for that space.

As far as veg/bloom switch goes, I dont have experience with those types of lights but i think the idea is to do veg only during veg and then both during flower. But i would say check the manual, Amazon ad, or do a Google search for exact make and model.

[Buds4949]

I have 4 greengo1200w lights started with only veg switched on plants weren’t growing so I did a little test for a week and turned on the bloom switches too big difference so I’ve left them both on the rest of my grow
only time I just use the veg is when there seedlings after that both are going

[Weed Pharma]

The veg switch must always be on- it usually controls the cooling fan!

[smoorman]

I have 8 1000w LEDs. On my 2nd grow. I believe they draw around 200w each with both switches on from the wall. I'd leave both switches on. Be careful, it may seem counter intuitive but LED's will burn your plants even though you can grab them anywhere and they won't hurt you. It's light burn not heat burn. Follow Mfg instructions unless you find your plants can tolerate them being closer. My different strains react differently to the proximity of the lights. All of these lights were around $100 each. Those are 5 gallon pots and 5 gallon buckets. I'm a couple weeks out from harvest.

[SoOrbudgal]

Fantastic fat bouquets of buds

[YYCannabis]

Both switches on for flower. As others have said, check the makers recommended height and start there. Pay close attention to node spacing in the main stalk for stretching, and attention to the top most leaves for light burn. Adjust as necessary.

[homegrown]

Running 2 viperspectra 600w in an approx 4x6' tent. 1st grow i used to move plants outside for sunshine, got too breezy one day so i put them back in the tent with VEG on..looked like they were in the shade! so i switched on the Flower...looked more like outside..so VEG and FLOWER are always on now lol. just looking at my units specs and im stretching their parameters. they recommend 28" minimum for Veg and 20 for Flower. First grow i went 22"Veg and 18-20 Flower. Second grow, in progress, Plants Veg'd at 18" and im waiting on their stretch to figure out where their gonna sit for this flower..
If they get much bigger,the plants are gonna decide the height. Im happy with my LED's, managed to get just over 1lb of awesome weed from first grow! This new grow is more of an experiment, testing lights, grow mix, food, and anything i thought i learned from the first grow....still learning hahaha

[SoOrbudgal]

I do pretty near the same thing as homegrown with my 2 450vipers. I'll veg. my seedlings for 2-3wks under t5 and cfl then move to tent. Depends on how well I see the seedlings doing strong and healthy I will put them under LED veg only for a couple weeks. Just to test and get them ready for both switches, i'm pretty cautious so I turn on both lights manually for a couple days get them use to it and see reactions. If stems and leaves are turned up reaching for the lights I set the timer for 18/6 on off both veg and bloom. Were talking photo period not auto. Veg only 28" both lights very tight node spaces I've found. Veg/bloom both on same height for light and man they start the stretch. I may put plants closer with risers and blocks of wood.