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Grow room heating

mrz1988

mrz1988

I'm just curious as to what all of you use to keep your grow room temperatures up and what temperatures you keep it at?

I've always just grown at ambient temperature which is around 68F in my house but I've decided that if I want optimal growth I should kick it up a few degrees. I've noticed that the change to my T5s from my LEDs have given a considerable upgrade in growth, which I am attributing mostly to heat. The heat at root level is around 70-72F with my closet open and 78-80F with it closed. I want to leave my closet open with a fan for airflow so I will need to bump up ambient temperatures in the room a few degrees for optimal growth. I might put a space heater on a timer for a few hours a day to keep temps up. Thoughts?
 
"I've noticed that the change to my T5s from my LEDs have given a considerable upgrade in growth,"

A sign of bad ventilation. I do not use T5 or led because I want my plant to grow!!! :cool:

Use HID with good cooling, it is the way.

You need a vent fan at the top of the room takng air out. I use inline fans. Look them up. Anything above 85F and spidermights will love it!!!!
 
careful with heaters in the closet bud....I would try and keep it closed as much as possible. Plants aren't gonna like 72. They will grow, but it will be slow.
 
cory_huck said:
careful with heaters in the closet bud....I would try and keep it closed as much as possible. Plants aren't gonna like 72. They will grow, but it will be slow.
Click to expand...

Plants aren't gonna like 72 :rofl:

The ideal temp of an indoor grow room is 75F. Do you know what temp. PEEK photosynthesis takes place at?
 
Hey, you should try to keep the night temps in the mid 60's to low 70's and they daytime temps around 78-82ish. Just make sure to get some fresh air ciruclarting on it and mabe even a light breeze to help build up plant strenth and make the stalk stronger.
 
Thanks guys. The LED itself gave pretty much no heat at all. The T5 gives me a good amount but not enough to burn plants unless I get REAL close which is why I like it. For the growing area I have and the amount of light I get I wouldn't trade it for any HID right now. I'm getting 40,000+ lux at peak output 1' from the bulbs, no need for more than that. Plus I've been reading that the newer bulbs I'm using have a superior spectrum to the MH so I'm giving that a go.

I'll try to keep it in the mid 70s or maybe a bit higher during the day and I think I can do that efficiently at only an hour or two of heating a day. I want to be able to keep my closet open for airflow that's all. The heater would be heating the room away from my plants and pushing that heat around the room and near my plants.
 
why don't you just put the fan in the closet, or get a smaller fan that will fit in there and keep the door mostly closed with just a small crack.. that way the temps stay mostly consistent? and they get the air flow they need... it's not so much that you need colder air flowing through as you need just air flowing around... keeping the door cracked a little will let some air vent out so it doesn't get to humid in there.. but I doubt it would get very humid anyways...

I had a space heater in my grow tent for the first 2 months and it was nice, I got one that had a thermostat built in for $40 and was oscillating, and even had a ECO setting in it, so it would switch from HIGH or LOW or whatever depending on the temp and how much power it needed.. but last month when I transplanted the majority of my plants into 1 gallon containers I kept the temps up to around 78-83 or so consistently even with the lights off. and I would use the inline exhaust fan to vent the area a few times a day to get the humidity out so it didn't build up ect.. only problem is that the electric bill went pretty high since it was on a lot of the time.. the ambient temps in the basement now are 65 or so.. so I just took it out for now and let them grow... when I had them on the tables in there (up about 3-4' off the ground of the grow tent) the temp where the plants were was 70-80 most of the time depending if the lights were on or not.. but since they are all in 1 gallon containers I need to put everything on the ground, and at "night" the temps are 65-66, and with the light on, I have the probe set on the soil kind of, so it is a little shaded, but the temp is only around 72-73.. since most of the heat is sitting in the upper section of the grow tent.. which kind of sucks but oh well..

and I just read an article a few days ago that stated that optimum photosynthesis was from temps 65-85, and anything above or below that made the rate drop.... so maybe next year I will be able to figure something out that will allow me to keep it warmer in there without having to use the space heater (I will use it most likely for a month or so to boost their growth, but then take it out)

and if you don't have room for the fan in there, like I said, just get a wall mounted one or something that you can fit in there, especially if you can get one that is just around the height of the light and can blow the air kind of down onto the plants.. if that makes sense.. so that way your moving the tops of the plants instead of trying to get air to blow through the stems... either way, your moving the stem, and it will strengthen it regardless.. but having it up higher might let you get some warm air circulated back down a little
 
I'll definitely consider this stuff. I'll have to go grab a few more cheap thermometers and put em all over the place and maybe do some experiments, but time is money as they say. If I can bump up the temps 5 degrees with two hours of space heating a day that's not that bad. Max, did you consider hooking the heaters up on a timer? Maybe instead of doing a HI-LO heating on a thermostat which will probably run at 1200/900W or something you could run a few hours a day at high on and off with a timer.

24 hours a day at low only (900W) would be 648 kWhrs / month... thats around $78 @ $0.12/kWhr just to run the heater. Ouch.
18 hours a day at low only would be 486 kWhrs / month
3 hours a day at high (1200W) would be 108 kWhrs/month or $13/month; just heat three times for an hour each and 4 hours apart and keep the room fairly insulated if possible, seems logical to me. Pretty big difference. I was considering this when thinking about the space heater but I suppose it depends on how fast it heats the room.
 
How big is the closet. I use a 150w hps in a 2' foot by 2-1/2' area. I will say LED are good but t5 are a waste of space unless your just vegging.
 
Right now grow area is 4' x 2' ish. Only have the light on half power. I'm using one of the newer T5HO models that has shown results consistent or better to a 400W HID but I'm running it at half of that until I need more space. I'm curious as to what you have heard about T5 and why they are a 'waste of space'? I'm mainly looking at the ability to get high lumen output at a very good spectrum without pumping out the heat. HID lights all pump out heat like crazy which means I have to move my plants further away. Further away means less light is reaching my plants, especially on the outsides. The newer T5HO bulbs have shown consistently that they can produce the same results as an HPS light or MH light will lower electricity costs and won't require the same kind of cooling. The 6500K/2700K dual color setup that I am using is providing me with an amazing spectrum that one wouldn't be able to discern from sunlight. The pot growers who tend to be miles ahead of us on lighting have said that watt for watt, the new T5s are passing the HID lights.
 
They do not have sufficient light penetration to flower, they are not as economical as a HID. As in they do not produce the same lumens per watt.




I can not really grow plants under fluorescents, once they go under HID they grow like they are under full sun.

There would be know way you could ever pass HID. You can have 1000W MH 3 feet above plants and get more light penetration then a T5 inches away. I am only telling you this from experience.
 
Nope they are still not as good. HPS produce up to 140 lumens per watt. HPS with the right bulb. Which is way more then the 95 the t5 you showed me. Also the t5 you show me only go to 2900k, a hps is 1900k, more fruite production.

HID WIN.
 
Well in general you're 100% right. T5s were always used for veg exclusively. They weren't great and there used to be talk about them only being marginally better than T8s. The thing is they're getting better every year, and in fact are starting to get better than HIDs. I bought into the LED hype a while ago but TBH I never got too convinced that they're better than the full spectrum lights. I'm going to have to wait until I'm a better grower to experiment more thoroughly with them. One thing I'm sure of is that a 90W LED won't come close to a 400W HID. It might do the job, but it won't measure up the same. The way I see it is if those who are growing crops that are worth their weight in gold rave about a light, I'd like to have it.
 
Thats for sure.

Those led and t5 get better and better. But if you look at the math HID produces more lumens per watt.
 
I use my wall heater, so that and the the heat from my 400w Mh keeps my grow tent at a cozey 80-87F during the day and i turn everything off so the low temp gets to about 70F in the morning when I turn everything on again
 
I'm only running 1 T5 HO 24" so far haven't needed to daisy chain the second one yet as I'm waiting for more seeds to pop. The first batch are with in 1-2" from the light and loving it so far. As for heat I actually wish they did give some off as there is none. I've always been told the closer the light the better regardless of what you grow.
 
Yes for starting seeds and vegging plants you can not go wrong with go old t5. I can see flowering and fruiting with t5, they have their advantages in they are very safe to run.
 
The point megahot brings up is a good one. HID lights might be better than the current top-of-the-line T5HO bulbs simply because they give you the heat you need as well. It depends on how you're going to try to heat your room. Chiles like more heat than most plants so the advantages of a higher heat-output light for chiles might outweigh even the new T5s.

As far as straight up lumens per watt that you're getting, the HID makes more. However, when you get to canopy lux per watt, the T5 is higher. The lux is what you really want because it tells you the light you're getting at the plants rather than the total light output by the light. The lux is higher for the T5 because you can move it closer to your plants than the HID.

I think I'm going to lower my light a bit and see if that increases ambient temps near my plants enough before I go fiddling with a space heater.
 
"The lux is higher for the T5 because you can move it closer to your plants than the HID."

That is just the issue. What makes HID so good is that they have huge spread and you keep them far away and plants still grow fast.

It is up to the grower but like I said I use a 150w hps in a 2'x2-1/2' area.

I will note those T5 look clean!!!!!!!!!!!!
 
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