?? Increase Watts in Flower or Not ??

BCJohn

Member
I wrote this in my grow journal then realized I probably should have put it here in the CFL forum. So here it is...

SO I think it is time to ask for some advice...

I am starting to actually get into the flowering stage of this grow. I am now seeing the development of pistils on the two White Widows. Little Mutant being farther along than the other. The two Lemon Kush I have now added are just starting so I am not factoring them into this question.

Question: Should I put in a second light fixture?? Should I double the number of CFLs in the tent??

I can easily create a second fixture that could add another 184 watts of light to the grow. I have already got the parts to increase the exhuast and scrubber function and a larger fan to circulate the interior air. The passive air intake comes up from the floor where the ambient temp is about 18 Celcius so I have some capacity to handle the increase in temperature that the added light will cause.

Will a doubling of the CFL watts to 368 watts be worth the added cost and heat concerns??


Can anyone give me some advice or opinions on this?
 

BCJohn

Member
If you go to my grow thread (in my signature)you will see a pic early on that shows the current fixture location as well as the two side Flouros that I have going. I would be adding a second hanging fixture. By putting a second one in it would push both towards the sides and tilt them so that they would be sending light straight down as well as from the two long sides.

A general increase in lighting to the entire plant is the idea. That is why I am asking if it is worth the cost, time, effort, and increased heat.
 

BCJohn

Member
Yep, add more light during flowering.:weed:
Is there a balance point between Watts and Heat production when you are working with a small space? Maybe a Watt per square foot that is optimal?

I know there are some discussions about this with the bigger MH/HPS setups, but they also factor in the vented hoods and other such. I am interested in the similar idea with CFLs.
 

perspextoe

Active Member
I'm on my first grow aswell(2 weeks in veg), and I think i have gathered from peoples posts on the forums would be that more watts is advantageous but its the placement of the watts which should be the key factor.

I guess if you think of a mj plant growing outdoors, it gets its light penetration around the plant from the suns movements during its daily cycle., so an indoor grow scenario we get the advantage of placing the lights to penetrate best,

Did I answer your question(dont know), but I would suggest checking whether your lights are penetrating enough and if not add more and work on that basis.

btw I plan to have 10 26W 2700 on each of my plants during flowering......
 

weediologist

Well-Known Member
i have 15x26watts(390wats) for 2 plants only in flowering i raise my wattage. I dont really care for veg. (156wats) i give it 2 months and save electricity incase of male plants.
 

BCJohn

Member
I think you guys are right about the placement vs wattage. I have a decent amount above if I have enough at the sides.

So, how do I know if the side lighting is sufficient?

I have two small 24" flouro lights at the sides. I just don't know what the output is for them. Should I try to go for a couple 23 watt bulbs on each side?
 

weediologist

Well-Known Member
most 24" are going to be no more then 17watts i think... so its better to have 23w or 26w(wat i use) for side lights i put 2 lights per side so 8 total so about 208Watts for the sides or u could just do 1 on each side and get 104watts for the side... and just leave the lights u have on top but have at lease 100watts per plant for the top.
 

BCJohn

Member
I'll have to look at the materials that I have and see what is possible. It's going to mean a trip to the store most likely if I go beyond a single bulb on each side. I'm pretty sure I have the parts for 4 bulbs. I just don't have any reflector materials. That isn't really a big issue since the whole tent is reflective but it isn't ideal.

I'll give it a try. An additional 92 watts would help... 184 watts would be better.

If I can double the watts I'll be at 107 watts per sqft. Or over 11,000 lumens per sqft... That is too much! Everything I have read says to stay under 10,000 lumens so that you do not exceed the suns normal output. if the sun puts out an average of 7,000 lumens and a peak of about 10,000 per sqft, I can't go over 11,000 lumens.

Is my math wrong here? 16 bulbs putting out 2600 lumens each? Divided by the 3.75 sqft grow area? That is over 11,000 isn't it?
 

BCJohn

Member
Bad Math!!
My mistake.

I used the Kelvin rating, not the Lumens... Stupid.

16 bulbs
1600 lumens each
25000 + lumens
3.75 sqft

Just under 7000 lumens per sqft. All good.
 

weediologist

Well-Known Member
i was going to say holy shit 41600 lumes with 16 cfl @ 2600 lol.... i have reduced my lights from 15 to 10 CFL so 16000lumens together from 24000lumens...it seems to grow the same so ill add the 5 cfls in the late flowering stage. how did u get only 3.75sqft... ur room is only 1.25'x3'? thats alot of lights for that small area am surprised u have not got heat issues.
 

BCJohn

Member
Small space for sure.
Heat control really comes down to the temp of the intake air. My intake is the bottom of the tent which is on the cement floor. Ambient temp at floor level is a steady 18.5-19 Celcius. That keeps my temps ranging from 20 at lights off to 28 at lights on. It has gone higher but not really past 30. Most of the time it is in the 27-28 range when I check it just before lights out.

I have put together an upgrade for my exhaust as well. That is why I think I can increase my lighting. Without the upgrade I wouldn't do it.
 

Sunbiz1

Well-Known Member
The more the better, only be careful with this...particularly when running indica doms.

The old rule of placing CFL's as close to plants as possible no longer applies when you begin upping wattage. I use over 1,000 actual W spread out over 24 mixed spectrum bulbs.

My sativa doms love it when placed 6" from lights, but the kush needs a good foot or becomes heat stressed.
 

BCJohn

Member
That is very interesting Sunbiz. So far my White Widow have been fine with the bulbs being 2-3" away. By the end of the day there are times when they have grown to about 1/2" from the bulb and I have to adjust back to 2". No problems so far with this process. They have all done relatively well. I have kept them very small, but I haven't noticed anything I would call heat stress.

I'll have to keep an eye on the Lemon Kush as they grow.
 

weediologist

Well-Known Member
damn maybe i should put my lights 2inch.... i have them 1/2 inch away from my plant...maybe i should let them stretch a little ... i want them lil taller.
 

Sunbiz1

Well-Known Member
That is very interesting Sunbiz. So far my White Widow have been fine with the bulbs being 2-3" away. By the end of the day there are times when they have grown to about 1/2" from the bulb and I have to adjust back to 2". No problems so far with this process. They have all done relatively well. I have kept them very small, but I haven't noticed anything I would call heat stress.

I'll have to keep an eye on the Lemon Kush as they grow.
It was the 6500K's that caused my heat issue...they do run pretty hot compared to 2700. I just kept adding a few bulbs every month, without ever raising the height...finally it caught up to me. I had to re-dial in on the entire set-up, monitor plants etc. to see how they responded to almost 1,100 actual watts in a 5X5X9 ft. ht area.

:peace:
 

BCJohn

Member
I think you're right about the 6500K's. I had higher temps with them than I do now with the 2600-3000K's. It was up at 30 Celcius most days.

Looks like I have the parts to add 4 bulbs, so I can bring the wattage up another 92 watts. That'll put me at 5120 lumens per sqft. Not bad. Not perfect though.

If I get 2 more 24" flouros I could have them vertical in the corners... 92 watts on each long side... and 184 watts above... That sounds perfect for my little tent. I would be getting about 8000 lumens per sqft! Of course that all assumes that I can fit them all in the tent. :lol:

I think I'll start with 4 more. No sense going to all the effort of building and buying more only to have issues with space.
 
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