Cob Lighting For A 4x8 Flowering Tent

[h4ppyf4rmer]

Finally completed the whole lighting as I hooked up the potentiometers to allow for dimming. Each driver is pulling 335W from the wall except the last one which is at 300W. I have determined the potentiometer only goes to 92K ohms which means that using this potentiometer on full means the lights are dimmed by 8% ... probably should get a new one or just disconnect it if I want full power...

I can dim the lights down to 50W from the wall (six COBs) before they hit a shutoff threshold.

 

[sixstring]

you can also wire a simple 2 pole on /off switch on the hot side of your dim leads going to the pot and just totally bypass that pot for full power which should be 105 to 108% rated power.thats how i wired up everything on that quantum/cob panel i have.dimmers full on the total power is like 740w then dimmed all the way down is like 100w.but with all 3 switches turned off i get 805w so its a big difference taking those cheap dimmers out of the loop with the 2 pole switches.

 

[h4ppyf4rmer]

you can also wire a simple 2 pole on /off switch on the hot side of your dim leads going to the pot and just totally bypass that pot for full power which should be 105 to 108% rated power.thats how i wired up everything on that quantum/cob panel i have.dimmers full on the total power is like 740w then dimmed all the way down is like 100w.but with all 3 switches turned off i get 805w so its a big difference taking those cheap dimmers out of the loop with the 2 pole switches.

yeah, that's a good idea. I did take note of what the power consumption difference was between the open dimmer leads (full on) with the potentiometer at 100%. The difference was only a couple of watts. I checked the "full on" resistance values of the potentiometers and two of them were at 102K ohms which I believe is enough to get the same results as the dimmer lines being open.

I have to wait to complete the overall bloom tent as I don't have enough cash to buy the two standup fans I want and the ventilation fan I want... maybe next paycheck };-)

 

[h4ppyf4rmer]

@sixstring I have a question you might be able to help me with:

I'm at the end of my 4th week of veg and plan on topping one more time before migrating over to the Bloom tent. I'm looking for a migration strategy for moving my veg plants under my vegging 180W purple light to my bloom tent with the COBs without shocking my plants...
1. I could move them now and run my lights at 1/2 strength under an 18/6 cycle for the next two weeks and just reduce the light time on the second week 1 hour per day until I reach 12/12.

2. I could flip the bloom light on in my veg tent now for the next two weeks and start reducing the light time per day on the second week to 12/12 before throwing them in the bloom tent

3. just wait two more weeks the way it's going and just toss them into the new bloom tent at full intensity on a 12/12 cycle...

not sure if it really matters other than I'm going from a fairly mild purple veg light to a REALLY FUDGEN BRIGHT white full spectrum light };-)

 

[sixstring]

I would choose option #3 just raise the lights all the way up and once the plants are in there lower the lights a little bit each day for a week if your worried.i veg under old ass shitty t5 lamps and always just carried the plants to flower with no issues.i did this for 7 years now under all types of hid including 1000w hps and 1150w gavitas.with my 600w hps i put the plants with a foot of the lamp and they love it.

 

[EventHorizan]

Was a pretty good read boys... Good job brother on the cob array build!
Nice clean work!

 

[h4ppyf4rmer]

Was a pretty good read boys... Good job brother on the cob array build!
Nice clean work!

Thanks, @sixstring is the man with lots of good advice!!!

 

[EventHorizan]

Thanks, @sixstring is the man with lots of good advice!!!

Oh I already know! And realstyles too! I done conversated with these boys a time or two...
There is some knowledgeable ppl here, from led, to cooling/AC, to hydro....

 

[h4ppyf4rmer]

and operational as of tonight... the problem is I think it's going to get too hot with the small exhaust fan that I have running. These plants are 4.5 weeks Veg

 

[sixstring]

what kind of temps ya got so far ?

 

[h4ppyf4rmer]

what kind of temps ya got so far ?

looks like I top out at 86 and then drop to 74 when the lights go out. I have the lights turning on at 8pm and off at 8am.

the outside temps around here have been in the mid to upper 80s during the day and upper 60s at night. all three banks of lights are pulling 300 Watts each (900 total) from the wall. The plants are 20 to 24 inches from the lights.

I'm running GH 1g:1m:[email protected] ec for the next two weeks and them 1g:2m:3b @2.0ec the rest of the way.

 

[sixstring]

you will prob need a decent exhaust fan for 900w like a 6 inch vortex pulling hot air from the top and out of the room.or just add co2 and roll with 86f thats perfect for it

 

[h4ppyf4rmer]

you will prob need a decent exhaust fan for 900w like a 6 inch vortex pulling hot air from the top and out of the room.or just add co2 and roll with 86f thats perfect for it

I don't want to do CO2, that just adds to the expense. I have the 4" exhaust currently above the lights where the open end is in the middle of the tent. At some point I may buy a 6" vortex but I don't want to throw the $150 at it just yet.

 

[h4ppyf4rmer]

soooo, looking forward, what could I do to enhance my current bloom lighting setup. I was not expecting the six plants to fill the whole 4x8 space as much as it did.

1. I could add six 2700K cobs to the current rail setup to bring the total to 24 cobs...
2. I could add some far red emitters
3. I could figure out how to add some quantum boards... just not sure how I would configure them with the current COB

I don't know if adding more lights would increase yield, there has to be a point of diminishing returns when it comes to lighting...

 

[EventHorizan]

soooo, looking forward, what could I do to enhance my current bloom lighting setup. I was not expecting the six plants to fill the whole 4x8 space as much as it did.

1. I could add six 2700K cobs to the current rail setup to bring the total to 24 cobs...
2. I could add some far red emitters
3. I could figure out how to add some quantum boards... just not sure how I would configure them with the current COB

I don't know if adding more lights would increase yield, there has to be a point of diminishing returns when it comes to lighting...

Im with sixstring! Your best bet is c02 tank and controller! It will battle the heat and it will give you a 20% increase in bud, pound for pound, the best option! I cant believe how fast these girls are growing! I can see there growth every day!

 

[h4ppyf4rmer]

Im with sixstring! Your best bet is c02 tank and controller! It will battle the heat and it will give you a 20% increase in bud, pound for pound, the best option! I cant believe how fast these girls are growing! I can see there growth every day!

Thanks, I just worry about CO2 in the basement as my daughters bedroom is down there. I've had a vasectomy, I can't make another daughter if she's overcome by a CO2 accident };-)

 

[EventHorizan]

Thanks, I just worry about CO2 in the basement as my daughters bedroom is down there. I've had a vasectomy, I can't make another daughter if she's overcome by a CO2 accident };-)

That is not gonna happen... Mine is right under my bedroom too..
If it was a problem the forces that dont like us would use that excuse to shut down home grows....
When is the last time you heard of some one dying from too much grow room c02 exposure :)

 

[h4ppyf4rmer]

The other problem I see is it's not a sealed tent, I push air out the top vent and by default the air is pulled in by the lower vents. Basically what I'm saying is, it would be much more than just adding a tank and regulator, I would have to figure out cooling as well.

 

[h4ppyf4rmer]

and I'm being rather entertained by the "Led's ??" thread, lol

 

[EventHorizan]

The other problem I see is it's not a sealed tent, I push air out the top vent and by default the air is pulled in by the lower vents. Basically what I'm saying is, it would be much more than just adding a tank and regulator, I would have to figure out cooling as well.

You are right about that! You will still need ac. You could prob get by with a 5000 btu...
here is what I did.. I got a room in the basement that I put 4x8 insulation board to seal it up pretty good, then i put a 4x8 tent in the room. I use 2 440 cfm fans to pull air out thru carbon filter and it mixes with the air in the room and then gets sucked back in theu the bottom vents of the tent.. I halfed the room off by running the tent long ways so that the window ac just cools that 4x8 space behind the tent, which is sucked in the tent QUICKLY,,
I leave the dehuey out side the tent to and hook it all to a autopilot environmental controller which has a probe in side the tent right above the middle of my canopy.