New Grower Where is the best place to put the temp sensor for thermo?

[buddro]

I have an indoor outdoor thermo. Where should I put the probe for proper measuring. I'm in a 5x5 tent with 2x 600w HPS, 24inch carbon to vortex to the two lights in cool tubes and out the tent to the roof. Two fans inside circing. Everything is insulated and I have a 10,000 btu portable ac blowing plumbs next to the tent into a space of about 3x4 that sits around intake and intakes cold air passively into tent.

Temps are 1 degree cooler in tent then in room when measuring from center of tent mid high. 77 in tent and 78 in room. I can lower my house Ac more if needed its at 77.

But when I lower the probe to the floor of tent and lights about 30 inches away it reads 85-88 degrees in tent and still 77-78 in room. Something doesnt sound right my ac box intakes low in the room and extraction up top should pull in enough ac to cool the tent. I'm fine with 77 but not past 85.

Where is the proper spot to place probe so I can adjust my system properly before adding my girls.

 

[HipsterDoofus]

I always want to know the temperature at the top of canopy.

 

[WVTurtle]

I'm curious to see the responses on this myself. Personally I've been putting my temp sensor right on top of my soil.

 

[buddro]

My temp is varying big time from floor level to mid height on tent. We are talking about a 7-8 degree difference also just got back from wally and added another fan so 3 total. I will say it helped to drop the fans below the carbon filter to make sure the carbon has a pocket of rising heat to capture at top. Also so fans dont recirc hot air from ceiling. Moving it lower helped temps by 1-2 degrees.

Crazy how the smallest tweaks make the biggest difference. I have been test running for two days and have tried numerous things like taping up 2 of 3 vents to create more negative pressure in tent. Still whatever I do it's a little hotter then I want. Think I'm going to grab a 4" vortex and use as intake Also no soil yet that comes next week after I work out the kinks and make sure tent is running like well oiled machine.

Right now lights are at 75% so 900w and temps are 79 floor level in tent 22 inches below light. Room is 76. Guess thats not bad 3 degrees off ambient but I would have thought more with my 10,000 btu ac running also.

I'm also curious where to go and want to make sure Im reading from right level so I can be confident temps are ok. When I open side window its cool and nice. What you guys think? Just want to make sure its right before the TD, White Cheese, and Blue Mammoth go in.

 

[Bonzo Mendoza]

Hmmmmmmm ... if you were me and I were you I'd proberably go down to the local thermometer store (I like swimming pool supply) and get me a nuther second thrmometer and stick it in a pot of soil so then I'd know #1 the temp at canopy level and #2 the temperature of the soil as it affects the roots.

The temp of the soil (roots) is probaberably not v. important unless it is either much colder or much hotter than the canopy .... but if there is a big diff, then you might wanna take action. For example, a pot of soil sitting on an ice cold cement floor would cause roots to get too cold altho the canopy is nice & toasty.

Me? I have mercury-glass thermometers hung all over everywhere - I love knowin' the temperature of everything. I learnt this lesson the hard way: first indoor MJ grow - a 100 bucks worth of cheese seeds turned hermie b/c the soil temp went up to 115 for two weeks (I wept bitter tears).

Personally I believe that MJ will grow between 60 - 95 degrees F (70-85 is best). Outside of that temp range ... don't bother wasting the time/money.

Lastly, I live in a climate that is tooooooo fookin' HOT to gro MJ outside June-Sept. INHO, the key is too find the straind that do well in the heat. One thing I know for sure, Durban Poison will do okay as sprouts in the heat. However, I have leanrt to use various tricks to keep things cool (like: ice at McDonalds' costs 99 cents for an 8 pouind bag; 3 bags w/ a fan blowin on 'em will keep lower gro room temp at the canopy about 5 degree F; this extends grow season about two weeks; yeah, I go to McD drive thru every morning at 7 a.m and eat junk food for breakfast those weeks)

 

[buddro]

Thanks for the reply. I have done many grows in rooms, and outdoors but this is my first tent run. How I stumbled upon this site. Strange when I step into tent with lights at 100% it feels cool and great. Cooler then any climate I've used, so I guess thats a plus. I can hold my hands on cool tubes as long as needed and if I put the back of my hand below the light 12-15 inches it barely gets warm feeling. Just was surprised such a swing in temps from floor to mid level of tent. Now that I boxed in my 10,000 btu unit cornering the wall of tent and the wall in room, intake is pulling a bunch of ac in tent now. Just cant believe its 84 on floor when the whole tent is very cool feeling and the 3 fans I got circ ceiling to floor well. Tent inside feels like a house with AC set to 71-72 inside. It's cool, know my thermo is good hung probe next to main unit they read the same, put it next to house ac thermo and showed the same. Maybe I should shade the thermo to get actual air temps and not temps from the light pounding on it, but wouldnt that negate the purpose being you dont want the canopy to burn.

 

[GoTgReEn]

I use 2..... One for canapoy temp and one for root zone.

 

[buddro]

Thanks I'm going to pick up another. Are you guys or gals running digital's or the ol'school ones

 

[Duck Commander]

I put mine at the top of my plants :smokebuds: Si

 

[GoTgReEn]

Thanks I'm going to pick up another. Are you guys or gals running digital's or the ol'school ones

Digital hygrometer ( temps and humidity ) about £10 at hydro store.