Should i take the deal?

Hey people

I've got 2 small grows each one in a tube with a diamter of 2 foot and a height of 5 foot, which i have run a screen across- for a scrog.

I have a large fan pulling about 60cfm through each, but I can increase that.

I had initially ordered 2 250w digital lumatek ballasts, from an online store, who are unable to supply them, but are offering me 2 400w at the same price.

I am unable to get the 250w anywhere else in aus, but have managed to source it from oversease for pretty much the same cost, including delivery.

It seems that a 400w would just be WAY to much light, at around 200w per square foot.

I figure i should just get my money back, and get the 250w from oversease, since even that seems excessive.

Any advice would be much appreciated.

Thanks
Grinch

2 400w hps isnt overkill.......

more light better buds simple !!1if u can, get more light lol,

Take the deal! As long as the temperature stays good, why wouldn't you go bigger. bigger is better... (unless its herpes)

Wow that was quick, thanks for the replys.

Is there a max lumen output, or is it just more is better. With the 250w i'll have just over 12500 lumens per square foot, and with the 400w i'll have just over 27500 lumens.
I've heard of light bleaching and light poisoning - do these occur at significantly higher lumens?

They guy offering me the upgrade said that the heat increase from the 250-400 was pretty minor....

Sounds like I'll be getting the 400w, didn't think i'd be up to that for years....

Wilsoncr17: hahahaha

Thanks again
Grinch

it wouldn't be 200w per square foot obviously it would be less (area of a circle not a rectangle)... but in the end the 400 watt would be ideal as long as you don't run into temperature issues. There is a certain limit to how much light the plants will use but you aren't close. The 400w will reach deeper into the canopy (due to the light intensity) and allow the buds to grow bigger. Just go for the 400w and don't worry about it unless heat is an issue. With the 250w you wouldn't be able to get buds of decent value any farther than 2ft from the bulb. With a 400w you can get decent growth up to 3ft away. DEFINITELY get the 400watts, it'll no doubt be worth it in the end.

Out of curiosity, are you getting 1 HPS and 1 Metal Halide? I figured you might alternate tubes between veg and flower so that you're getting buds every 2 months rather than every 4 and keeping your electric bill consistent.

there is a max, a plant can only use so much light at once. and there is a thing called "light poisoning". you also will have a lot more heat to deal with.

fdd2blk: would you advise against using a 400 in my area? I can get as much as 100 cfm going through each space if needed....

I found these on another forum, so if anybody could confirm....

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10,000+ Will bleach your leaves rendering them useless (thanks smokinrav).
7,500-10,000 Will cause optimal growth with the potential for bleaching of leaves the closer you get to 10,000.
7,500-8,500 Is the right range with good CO2 enhancement.
7,500 Is the magic number for most conditions.
5,000-7,500 Internodal spacing will be tight and bud mass will increase the closer you get to 7,500.
2,000-5,000 Bud mass will continue to decrease and internodal spacing will open up the closer you get to 2000.
<2,000 Plant will appear scrawny and yeild very poorly.
500-1,000 Ideal for cloning
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Light Requirements of "High Energy" Plants
1000 - 5000 lux Min. necessary for life
10000 - 15000 lux Min. necessary for consistent but sparse growth
20000 - 25000 lux Min. necessary for robust growth

25000 - 30000 lux Max. Efficiency for Sub Tropical varieties
25000 - 50000 lux Max. Efficiency for Equatorial varieties


Plants need 25000-50000 lux too grow fast.


90000 lux Max. Sunlight Intensity on Earth's surface This is too much light, it is not good for the plant.

Plants subject to intensities at this level or greater are at risk of "solarization," whereby photosynthesis is retarded. This can happen at noon on a clear Tropical summer day, especially at high altitudes.


140000 lux Sunlight above atmosphere (Solar Constant)

10000 lumens per square foot = 107639.104167 lux
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The 2nd one seems more 'scientific' but that doesn't mean its correct....

With the 400w and Philips Son T Agro rated at 55000 lumens, i will have 17507 lumens per square foot, which is 188443 lux.
Either way, if the info above is correct, i'm giving way to much.

A 250w and Sylvania SHP-T rated at 23200 lumens, i will have 7384 lumens per square foot, which is 79480 lux.
If the first bit is right, this is perfect, if 2nd is its still way to much.

HELP!@!@!
Grinch

We have done grows, we don't need the mathematical interpretations to know what is needed. That 250watt bulb will be enough but that 400watt will be better. The only time you should consider the light-jargon is when considering which types of lights to use. When it comes down to the simple fact of how big your grow area is, that 400watt will be perfect and 250watts won't be as good. Trust us, you won't be giving those plants too much light.

Besides... simple fact remains if you THINK you are giving them too much light (which isn't going to happen with only 400 watts) then you can just move the lights 6-12 inches farther from the plants...

Redeflect: Sorry mate, didn't see your original post - I'll be running each tube independently, with mh for veg then hps for flower. I've never tried a sativa before and want an indica and sativa growing - I'll be regenerating the plants to see if there's any truth behind the rumour that older root stock bares sweeter fruit - for ganja. I also don't have room to have 2 flower tubes, a clone area and/or veg area. The 2 plants will be 1 - 2 months appart.

So I should just disregard those charts - are they just bullshit?

Assuming heat wasn't an issue, would it be worth getting a 600w for flower or should i stick with the 400....

lol, if heats not an issue i'd get a 1000w myself.

The Grinch said:

Redeflect: Sorry mate, didn't see your original post - I'll be running each tube independently, with mh for veg then hps for flower. I've never tried a sativa before and want an indica and sativa growing - I'll be regenerating the plants to see if there's any truth behind the rumour that older root stock bares sweeter fruit - for ganja. I also don't have room to have 2 flower tubes, a clone area and/or veg area. The 2 plants will be 1 - 2 months appart.

So I should just disregard those charts - are they just bullshit?

Assuming heat wasn't an issue, would it be worth getting a 600w for flower or should i stick with the 400....

Click to expand...

those charts are correct. a plant can only use so much light. too much light will burn the leaves and bleach out the color. i have seen it happen. you won't get twice the bids with twice the light, once yuo reach the optimum. there is a limit.

revegging is not worth it. IMO, ... https://www.rollitup.org/advanced-marijuana-cultivation/54004-re-vegging-my-hijack.html

i'm a bit confused.... if the charts are correct, then i should be sticking with a 250w....

Well I did order the 400s, I'll test them for a grow or 2, and if i need to I have a mate that will take them off my hands.
Just prefer to not waste time, growing and then killing my plants.

Reveg is more a matter of necessity than choice. For an indica I could take a clone at 2nd week of flower, put in stasis for 4 weeks, then veg for 2 weeks as plant finishes - I might have room for that. But have no idea how i'd do it with a sativas 3-4 month flower period.... Sweeter buds would just be an awesome bonus of being able to keep a nice plant gowing.

The Grinch said:

i'm a bit confused.... if the charts are correct, then i should be sticking with a 250w....

Well I did order the 400s, I'll test them for a grow or 2, and if i need to I have a mate that will take them off my hands.
Just prefer to not waste time, growing and then killing my plants.

Reveg is more a matter of necessity than choice. For an indica I could take a clone at 2nd week of flower, put in stasis for 4 weeks, then veg for 2 weeks as plant finishes - I might have room for that. But have no idea how i'd do it with a sativas 3-4 month flower period.... Sweeter buds would just be an awesome bonus of being able to keep a nice plant gowing.

Click to expand...

you're confused because you are listening to people who don't know. "oh yeah, more is ALWAYS better".



if you want to reveg, take a cutting. it will be 5 times faster. you don't get "sweeter buds" when you reveg. it's all the same.

fdd2blk: so was i wrong to get a 400w for my space? I can increase the grow space by a foot if i had to, just require some big mods. At the moment its about 5 foot of grow and light space - 5 foot tube on top of the bucket.

I'm not so worried about time taken for reveg its more the space required to take clones.
If I were to take a clone in 1st week of flower, how much light would keep it healthy, but stop any significant growth - or would I have to keep trimming it until I was ready to veg.

Thanks
The Grinch

You are probably better off just getting one or 2 more 250W and move them around IMHO. 400W produce too much heat by themselves.

The Grinch said:

fdd2blk: so was i wrong to get a 400w for my space? I can increase the grow space by a foot if i had to, just require some big mods. At the moment its about 5 foot of grow and light space - 5 foot tube on top of the bucket.

I'm not so worried about time taken for reveg its more the space required to take clones.
If I were to take a clone in 1st week of flower, how much light would keep it healthy, but stop any significant growth - or would I have to keep trimming it until I was ready to veg.

Thanks
The Grinch

Click to expand...

you can take a clone and put it under a single CFL and it will stay small forever.

Xeno420: Gonna test it this summer - 3 months - and see how I go with heat. I have an airconditioner if heats a massive problem and if it is, i'll give to a mate and get 250s for the next grow.

fdd2blk: Once rooted, how much, if any, would i feed it - or would distilled water be ok... I've been using AN but about to start lucas formual, so have both nutes

The Grinch said:

Xeno420: Gonna test it this summer - 3 months - and see how I go with heat. I have an airconditioner if heats a massive problem and if it is, i'll give to a mate and get 250s for the next grow.

fdd2blk: Once rooted, how much, if any, would i feed it - or would distilled water be ok... I've been using AN but about to start lucas formual, so have both nutes

Click to expand...

i'm in soil. i use tap water. a little food might be good.