should i......

should i use my 125 watt cfl and have the temps at 76 or should i use the 250 watt and have the temps at 82? these are the two lowest temps i can get with these lights, what do you think i should do?

either temperature is absolutely dandy

/\ not really if 82 is the lowest with the 250 whats the highest thats what is going to answer your question because as the plant get bigger your temps are going to go up. I say start with the 150w and start saving for a 4'' -6'' inline cause If your going to buy a fan you might as well buy something you can use later when you upgrade to an hid setup.

certainly if it can go much higher then it's an issue, but if he is stating he can get it to 82 then that means he can keep it at 82, else what is the relevance of that temperature? he would be asking how hot is too hot.

85-87 your in the danger zone. If he is starting and is just doing runs bare with no plants in his area he and you may not realize as the plant get larger the temp will go up plants do produce some heat of there own during respiration

During the respiration phase plants become exergonic (they release heat). Converting primarily glucose, but proteins, fats, and other carbohydrates too, they release heat at the rate of -686 kcal/mole of glucose or -2,870 kJ/mole of glucose. I bet you're sooo glad you asked. ;o)

and ambient temperatures will play some effect also the temperature outside his grow area

so say he did his test run on a day that it was 67f and with the 250w bulb the room reached 82. On a warmer day of say 72 that room with the same ventilation the room would reach approx. 87F then factor in the addition larger plants with high metabolisms mind you the added volume from his growing medium retaining heat while lights off and he could reach 90 In this condition his plants will be transpiring like crazy sucking massive quantities of water from the soil he forgets to water and those things are going to be as flaccid as can be.

It has happened to me before this is not a fairytale it is of my own experience
so that being said I retain my original statement.

i'm just replying in regard to the info he has posted. if he made a thread about having the temperature at 82 then i am assuming he is smart enough to be taking your points into account, and that 82 is his average temperature. your points are spot on though.

for the record though, from experience, 85-87 is anywhere but the danger zone. certainly it's not the optimal temperature, but did little wrong at all.

at the end of the day your points revolve around what the OP has actually taken into account.

i already have an inline fan and 2 outtake fans, the plants is flowering as we speek, its an auto, its about 16 inches tall so far, there only suppose to get between 10 and 15 inches, this is only in a small cabinet, i have not used the 250 watt when it has been hot outside yet, it would probs get to hot when its hot outside, i know the 125 watt is good all round, heres some pics of the box, the duck tape holds the door shut lol the two outtake fans are behind the light, the scabby white board you can see round the intake is only till the mylar gets delivered

i will post a pic of the plant in 2 minutes, they are old photos so the plant you see in pic 4 is not how it looks now

Fisherman Pete said:

i'm just replying in regard to the info he has posted. if he made a thread about having the temperature at 82 then i am assuming he is smart enough to be taking your points into account, and that 82 is his average temperature. your points are spot on though.

for the record though, from experience, 85-87 is anywhere but the danger zone. certainly it's not the optimal temperature, but did little wrong at all.

at the end of the day your points revolve around what the OP has actually taken into account.

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Well in regards to the limited amount of information that was provided I couldnt really be more generalized and specific. So I decided to be more generous with the facts. 85-87 may be ok If you keep your op on lockdown and keep everything watered well enough note I say danger not dead. 88-90 not good 91-95 your leave are shriveling.

Keep in mind this is in regard to indoor containerized plant. Outside is a different story
ground temperatures stay a fair amount lower I believe 2ft down and its stable at about 56F probably varies with your latitude though. Your root temperatures are what is most important If your roots are cool your plant will be too think of it like a radiator the cool water moves upward into the plant.

This is why it really confuses me that they make pots black considering black holds a ton of heat I suppose it has to do with light being able to penetrate white plastics easily and the fact that light is detrimental to roots. Pots that are white one the outside and black on the inside would be prime and you would get more from your light because of the reflectivity of white and you could safly run slightly higher temperatures, the roots would stay cooler and the water wouldn't evaporate from the soil as quickly

in that case i'd listen to svchop and stick with the 125. if you've yet to try the 350 under hot ambient temperatures then it's not worth the risk until you know for sure. for reference i run a 300w CFL in the grow tent cloning station just fine without any fans or extraction.


once it starts to heat up by all means trial the 250 as more light = yay!

yeah probs better to stay with the 125, would it be a bad thing to keep it on the 250 and on hot days change it back to the 125 or would this freek the plant out

no man I was just going to say that if its cool enough pop that bulb in It will be like a bright sunny day for the little girl the 125 will bee like partly cloudy. Only thing I can think of that could upset would be if the bulbs where of different spectrum's.

both the 125 and the 250 that are in question are red

should be no issue then, what color are the pots they are in?

the colour of the pot is an orange sort of colour, you can see it in this older photo, this is a photo of the plant before i had to bend it over as it was getting to tall for the unit

Well at least its not black. I see your intake but your exhaust is it directly above? I also notice that you have your ehaust side by side you might bennefit by separating them the opposite sides of the cabinet to create a more turbulent airflow, turbulent air hair a more even temperature with less hot spots.

no the intake is on the side of the box at the height of the tops of the pots and the outake is on the back at the top, i did think about putting the outtakes seperate but i thought i would put them together to get the heet away from the light

JimmyTheJaw said:

should i use my 125 watt cfl and have the temps at 76 or should i use the 250 watt and have the temps at 82? these are the two lowest temps i can get with these lights, what do you think i should do?

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Install some ventilation and go as big as possible.

JimmyTheJaw said:

should i use my 125 watt cfl and have the temps at 76 or should i use the 250 watt and have the temps at 82? these are the two lowest temps i can get with these lights, what do you think i should do?

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I think you should use the 250 w. 82 degrees is alright.