What happens if I dont have higher temps with led?

I am about to start my next run and am still deciding if I should veg with QBs or 315 cmh.

Its starting to get colder again and I am not sure If I will be able to maintain temps in the 80s like is common when using led.

If i have temps in the mid 70s will there be any negative impact? If so I'll probably use cmh for veg and both for flower.

Thanks for your input.

chronnie49 said:

I am about to start my next run and am still deciding if I should veg with QBs or 315 cmh.

Its starting to get colder again and I am not sure If I will be able to maintain temps in the 80s like is common when using led.

If i have temps in the mid 70s will there be any negative impact? If so I'll probably use cmh for veg and both for flower.

Thanks for your input.

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You have the right idea, use the CMH for veg and both for flower if you will have issues staying above 80F. The CMH will help keep the leaf surface temps up.

NukaKola said:

You have the right idea, use the CMH for veg and both for flower if you will have issues staying above 80F. The CMH will help keep the leaf surface temps up.

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What will be the negative impact if temps are below 80 with led?

You may experience slower growth. Different patterns of uptake for water and nutrients. What if you went with the led, but had the CMH turn on on a timer for 15 minutes at a time to get the heat up periodically.

SnidleyBluntash said:

You may experience slower growth. Different patterns of uptake for water and nutrients. What if you went with the led, but had the CMH turn on on a timer for 15 minutes at a time to get the heat up periodically.

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Why not just run a small radiator type heater or perhaps seal up the area you are growing in so you can capture more of the heat your LEDS emit?

chronnie49 said:

What will be the negative impact if temps are below 80 with led?

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Lower leaf surface temps will slow plant metabolism.

LED's are great for efficiency but the room temp needs to be higher because much of the heat is radiated upward which results in lower leaf surface temp compared to HID's which direct the heat down to the plant.

Instead of running a heater and the LED, you would be better off just running the CMH.

I'm not sure how you are cooling your room, if you have inline fans for intake/exhaust you can connect them to a thermostat, variable speed controller, or recycle timer if they are currently running @ 100% to help slow the exchange of air and increase temps.

farmingfisherman said:

Why not just run a small radiator type heater or perhaps seal up the area you are growing in so you can capture more of the heat your LEDS emit?

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I think I would just use the cmh instead of the led with a heater but thanks for your input.

veg with cmh and flower with LED and CMH more light and a better spectrum would be good for your plants

NukaKola said:

Lower leaf surface temps will slow plant metabolism.

LED's are great for efficiency but the room temp needs to be higher because much of the heat is radiated upward which results in lower leaf surface temp compared to HID's which direct the heat down to the plant.

Instead of running a heater and the LED, you would be better off just running the CMH.

I'm not sure how you are cooling your room, if you have inline fans for intake/exhaust you can connect them to a thermostat, variable speed controller, or recycle timer if they are currently running @100% to help slow the exchange of air and increase temps.

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Yea I will just use the cmh if temps are too low to run the led without a heater. My last crop just finished drying in the tent so I havent done any temp testing yet.

I just use an 8 inch inline fan on a speed controller for cooling.

chronnie49 said:

Yea I will just use the cmh if temps are too low to run the led without a heater. My last crop just finished drying in the tent so I havent done any temp testing yet.

I just use an 8 inch inline fan on a speed controller for cooling.

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You can try turning the fan down to a lower speed and even adding a recycle timer so it comes on for say 1 minute every 4-5 minutes to help raise temps.

Also when I'm flowering with two 220 watt qbs and two 315 cmh if the temps are in the 70s would that be ok since the cmh would increase leaf temps?

NukaKola said:

You can try turning the fan down to a lower speed and even adding a recycle timer so it comes on for say 1 minute every 4-5 minutes to help raise temps.

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Yea I'll do some temp testing and see how its looking.

My plan is to start 6 seedlings in a 2x2 with a 110w Alibaba sf1000. Once they get bigger I will move 4 of them into a 5x5 for the rest of veg and flower and keep 2 in the 2x2 for veg and flower.

chronnie49 said:

Also when I'm flowering with two 220 watt qbs and two 315 cmh if the temps are in the 70s would that be ok since the cmh would increase leaf temps?

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I would try to shoot for the high 70's or low 80's with the CMH in the middle. If you control your inline with a speed controller and recycle timer you should definitely be able to dial in the temp with 755w in a 5x5.

NukaKola said:

I would try to shoot for the high 70's or low 80's with the CMH in the middle. If you control your inline with a speed controller and recycle timer you should definitely be able to dial in the temp with 755w in a 5x5.

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I'm going to use 2 cmh so I'll have 1,070 watts if I turn the led all the way up.

I was planning on setting up the lights qb cmh qb cmh. You think it would be better to have both cmh in the middle and the led on the outside?

I try and point airflow blowing on top of the LED downwards to extract as much heat from the led and blow it downwards to warm the area. Use both is a good idea. More light. More heat. Cons- more electricity

SnidleyBluntash said:

I try and point airflow blowing on top of the LED downwards to extract as much heat from the led and blow it downwards to warm the area. Use both is a good idea. More light. More heat. Cons- more electricity

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Thats a good idea to blow the heat down on the canopy. I'd really like to use the 110w qb in the 2x2 so I'll get a laser temp gun and see how temps are looking.

I'm not too concerned about electricity costs. I pay 15 cents per kwh and weed is expensive and shit quality where I live so I still save a lot of money and get to smoke quality.

chronnie49 said:

I'm going to use 2 cmh so I'll have 1,070 watts if I turn the led all the way up.

I was planning on setting up the lights qb cmh qb cmh. You think it would be better to have both cmh in the middle and the led on the outside?

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If you have 2 CMH then yeah I would run them alternating like you mentioned.

chronnie49 said:

I am about to start my next run and am still deciding if I should veg with QBs or 315 cmh.

Its starting to get colder again and I am not sure If I will be able to maintain temps in the 80s like is common when using led.

If i have temps in the mid 70s will there be any negative impact? If so I'll probably use cmh for veg and both for flower.

Thanks for your input.

Click to expand...

I keep my flower room at 81 and have no issues. 1110 watts of quantum boards. I don't think you will have any problems in the mid 70's. If you need to throw in a cheap electric radiator. I use them in my basement throughout the winter months during lights off.

jonnynobody said:

I keep my flower room at 81 and have no issues. 1110 watts of quantum boards. I don't think you will have any problems in the mid 70's. If you need to throw in a cheap electric radiator. I use them in my basement throughout the winter months during lights off.

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Luckily I have built in wall radiators in every room which I use in the winter during lights off also.

I'm taking 10 days off of work next week so that will give me time to get the seeds started and see how my temps are looking in both tents.

Hows that Alibaba light working out for you?

chronnie49 said:

Luckily I have built in wall radiators in every room which I use in the winter during lights off also.

I'm taking 10 days off of work next week so that will give me time to get the seeds started and see how my temps are looking in both tents.

Hows that Alibaba light working out for you?

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Love the built in radiators. That's very convenient. The light from alibaba is doing great. The differences between the name branded spider farmer board and the alibaba no name quantum board are minimal. The no name board does not have the same size panels as the spider farmer unit. However, because the no name board has 6 panels rather than 4 it is larger than the name brand unit , has more diodes, and pushes more power to each diode. Specifically the alibaba light measures 29.52" x 23.62". The name brand board measures 25.5" x 21.1". The no name unit is about 4" longer and 2.5" wider than the name brand unit. The name brand board has 1212 chips. The no name board has 1308 chips. I will order another unit from alibaba when the time comes for the next expansion. Both units are great lights, but I got more value for my money with the alibaba light. It pushes out more light and spreads that light over a significantly larger foot print for about $125 less than the name brand board. I received excellent customer service and shipping was quick. I have both the name brand board and the no name board in my flower room killing it along with my existing two 2000W hortilux HPS lamps.