New to 20X30 grow room. Need advise.

DoubleAtotheRON

Well-Known Member
This is absolutey incredible! This is one hell of a setup!! Very well done. Wondering if you track the consistency of the rooms temp and humidity levels? I’m not sure if I’m overthinking my setup and chasing my tale. Between my split AC run cycle and venting for humidity I’m having a fluctuation of 5’F and 5% RH and this cycles every few minutes. Would you think this is ok or going to stress the plant. Appreciate your feedback as you clearly have it figured out.
Fluctuations of 10 degrees f is no problem between your lights on/off. RH we control depending on what phase we’re in. We have 2 4000 sq ft dehumidifiers in there. In veg, we run it about 65%, and dial it down in flower to 45 or so. We ran about 25 more plants this run, and had a hard time getting the RH down where we wanted it ...more plant mass=more RH, and we did find a handful of tight top Cindy99‘s with slight bud rot. (tossed those). But overall, I think if you can get your lights off temps to the mid to upper 60’s, I think it helps with your terp profile... we’ll find out Friday when our lab results come back if this helped.
 

LoganGP

Active Member
Fluctuations of 10 degrees f is no problem between your lights on/off. RH we control depending on what phase we’re in. We have 2 4000 sq ft dehumidifiers in there. In veg, we run it about 65%, and dial it down in flower to 45 or so. We ran about 25 more plants this run, and had a hard time getting the RH down where we wanted it ...more plant mass=more RH, and we did find a handful of tight top Cindy99‘s with slight bud rot. (tossed those). But overall, I think if you can get your lights off temps to the mid to upper 60’s, I think it helps with your terp profile... we’ll find out Friday when our lab results come back if this helped.
Thanks for the reply! My temp and RH fluctuations are while lights on. It happens between the AC on off cycles as it cools. Just wasn’t sure if it’s ok for the rapid fluctuations. I’m thinking it’s cause my room is small. 8x10. I do lower the temps 10f at night but same thing it is constantly fluctuating. I use a cheap inkbird temp/humidity sensor with datalog to track the climate.
 

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DoubleAtotheRON

Well-Known Member
Thanks for the reply! My temp and RH fluctuations are while lights on. It happens between the AC on off cycles as it cools. Just wasn’t sure if it’s ok for the rapid fluctuations. I’m thinking it’s cause my room is small. 8x10. I do lower the temps 10f at night but same thing it is constantly fluctuating. I use a cheap inkbird temp/humidity sensor with datalog to track the climate.
I see what you're saying now. Hmm.. Sounds like your AC unit is too big for the room. My brother has been in HVAC for 35 years, and he's always told me that you CAN have a unit too large in tonnage for a room, home, etc. Too big of a unit will make it cycle too often, which sounds like your case here. Only thing I would try that I can think of is to increase your exhaust port, and drop the temp in the room. Im not familiar with your setup, but try a max of 75 degrees, and get some more exhaust moving.
 

LoganGP

Active Member
I see what you're saying now. Hmm.. Sounds like your AC unit is too big for the room. My brother has been in HVAC for 35 years, and he's always told me that you CAN have a unit too large in tonnage for a room, home, etc. Too big of a unit will make it cycle too often, which sounds like your case here. Only thing I would try that I can think of is to increase your exhaust port, and drop the temp in the room. Im not familiar with your setup, but try a max of 75 degrees, and get some more exhaust moving.
Yea I think that may be the case. your right. I’m Running led and they don’t put off much for heat. Maybe I’ll just have to add more ;) Thanks for the help.
 

2com

Well-Known Member
Fluctuations of 10 degrees f is no problem between your lights on/off. RH we control depending on what phase we’re in. We have 2 4000 sq ft dehumidifiers in there. In veg, we run it about 65%, and dial it down in flower to 45 or so. We ran about 25 more plants this run, and had a hard time getting the RH down where we wanted it ...more plant mass=more RH, and we did find a handful of tight top Cindy99‘s with slight bud rot. (tossed those). But overall, I think if you can get your lights off temps to the mid to upper 60’s, I think it helps with your terp profile... we’ll find out Friday when our lab results come back if this helped.
I thought 10*F diff in day night temp (not rh as well..right?) was sorta both a somewhat recommended and max differential. Is that wrong? I thought differences over 10*F were bad for mold and other stuff. (But then again, this is probably ambient temps, and now with led and stuff, things are different).

Thanks.
 

DoubleAtotheRON

Well-Known Member
I thought 10*F diff in day night temp (not rh as well..right?) was sorta both a somewhat recommended and max differential. Is that wrong? I thought differences over 10*F were bad for mold and other stuff. (But then again, this is probably ambient temps, and now with led and stuff, things are different).

Thanks.
I dont think it's that big a deal if you're in the correct range for the phase you're in. Veg is going to have higher temps (not too high), and late flower is going to have lower temps lights on, lights off towards the end to mimic fall. At the end of flower, I will lower the night (lights off) to low to mid 60's, and ~73 lights on... You don't want to cook your terps.
 
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DoubleAtotheRON

Well-Known Member
Thanks for the reply! My temp and RH fluctuations are while lights on. It happens between the AC on off cycles as it cools. Just wasn’t sure if it’s ok for the rapid fluctuations. I’m thinking it’s cause my room is small. 8x10. I do lower the temps 10f at night but same thing it is constantly fluctuating. I use a cheap inkbird temp/humidity sensor with datalog to track the climate.
What ton is your mini spilt for the 8x10? Like l said, if your unit is too big for the room, you just have to make it work harder by whatever means.... or try setting in in Auto mode instead of Cool only. We have a 2 ton Carrier in this 20x30, and it runs almost all of the time. Cycling on and off every few minutes is hard on the compressor and other parts, so you're breaking down the life cycle of your unit over time.
 

LoganGP

Active Member
What ton is your mini spilt for the 8x10? Like l said, if your unit is too big for the room, you just have to make it work harder by whatever means.... or try setting in in Auto mode instead of Cool only. We have a 2 ton Carrier in this 20x30, and it runs almost all of the time. Cycling on and off every few minutes is hard on the compressor and other parts, so you're breaking down the life cycle of your unit over time.
I have a 1 ton mini split. Yes it was on cool mode only. I just changed to auto mode as you suggest and Lower temps to about 78 rather than 82. I’ll see how this works out over the next 12 hrs. Appreciate the help!
 

LoganGP

Active Member
Hey there,

after chatting I went and played with the ac. This is a new setup and first grow so I’m a bit overwhelmed. I had the ac set to cool but the fan was on HIGH setting. That was a good part of the problem. I now have the ac set to cool but have the fan on LOW. I’m only getting a 4f temp fluctuation now. I tried full auto and was not the ticket.
 

LoganGP

Active Member
I use three temperture hygrometers for a 5x10x7 room. They all read within a few degrees of each other.
yea a couple spots. It seems I have it locked down to 4°F fluctuations and 4% RH. I have lots of circulation. I had some plant issues as well with possible overwatering or flooding them too fast and not getting good saturation in the soil. They are looking a little bit better in the last couple days. I drop the heat also 10°F down to 75°F from 85° F and the RH is at 62% now from 72% RH. For a medium mix I am running a 1/3 happy frog potting soil 1/3 perlite and 1/3 pro mix HP. I was trying to run 1200-1500ppm CO2 at first as well with the high temps. But with so much changed from when I brought them from my veg tent into the new shed they got stressed out maybe even a nutrient overdose. But as mentioned they seem to be doing a little bit better I’m at 10 weeks veg pretty, sure the last couple weeks in the shed just stunted them and not much progress. I also did a heavy defoliation six days ago. Well I Definitely learnt a few things over the last few weeks and how to smooth things over for the next run. I have Sour diesel and Ok Kush in here. Not sure what ones are what lol.
 

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DoubleAtotheRON

Well-Known Member
If you remember, how did the Sour D come out, and who did you source the beans from?
Thanks
The Sour D came out very well!, prob one of our best yields from CropKing. I wouldn’t mind doing it again, but so many Dispo’s carry it. The Ethos line we just finished up are not for beginners for sure, but Sour D is very easy to grow. Hang on, and I’ll see if I can find the lab results on that one.
 
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