Is it possible to turn the ac down to a lower temp? If you think about the fact that you are bringing in air at say 80 degrees, if the tent is hotter than that, you need to offset the heat inside the tent with the right amount/right temperature of air, to bring the temperature down to where you want it. If it was me, I would adjust the input until you reach the desired temp. And if the in and out fans are adjustable, play around with the exhausting of the air as well until conditions are ideal.
Do you have a home depot? They sell spot coolers but you still need to duct the hot condenser air out of thespace
I have a 195cfm fan w/ducting going out of the grow and a 195cfm w/ducting going in, both on 24/7. House thermostat is programmed 79/day, 80/night. as I speak I am freezing 1/2 gallon and 1 gallon water jugs to see if either or both will bring the temp down. I’m also considering modifying the floor vent in the room to accommodate a 4" flange to connect it directly to the “in” inline fan. The room is cooler than the house but I definitely need to chill the grow.
Question: my inline has the fan in grow room and the ducting runs to the exterior (room). Should it be reversed? Fan in the room ducting in the grow? Pull vs push the air? I appreciate all your input(s) so keep them coming and I’ll keep you updated. fyi - it’s day 2 for 1 of my healthy windowsill seedlings and it’s still alive, waiting for 2nd plant to show roots before moving it to the grow.
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I’ve also ordered cal/mag nutes and lowered my light to 12". 1/4 strength eh?
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@Dorf, your grow is in a 4x4/5x5 space right. OK so lower the AC unit 2 to 3° also instead of your 195 in-line fan bump that up to a 390 CFM or higher which is going to be a 6 inch. And if you run into any more issues with that then I would get a Y ducting like I have, that way you’ve got two ports of fresh air coming in and then have your 195 suck out all your humanity that’s how I do it. Hopefully this works for you brother let me know if it does because he sure is working for me and just FYI all five plants that were in my 4 x 4 tent I got a little over 2 1/4 lbs, I wish we would’ve vegged Runtz for more weeks and let that baby get about 5 feet tall I’ll do that next indoor grow with Runtz. Well I look at that as a job well done considering I have never grown in a tent before I’ve only grow trees outside. Good luck with your grow, happy growing
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@Dorf sorry if you stated it above already, but are you exhausting out the top and intake through the bottom? That’s how it should be if not. I am personally running only exhaust fan out the top port, with passive intake coming in through the bottom opposite side mesh vent. The volume of air coming in needs to be lower than the grow temp if you want to bring down temps. If you are pumping 79°air into a grow with heat sources, then that air is going to be heated up even more. I would either turn the ac down or make a deflector to direct more of the ac toward the tent as a cheaper option. I wish my tent was in a temperature controlled environment, I’m trying to bring down temps in a basement setting that already stays warm because of the dehumidifier.
But anyway, there will also be a point where you can bring in a high enough volume of air and basically have the same temps in and out of the Grow. That would be achieved by a higher CFM fan.
I would also shoot for either equal pressure inside, or slight suction to avoid too much humidity too. Everything you do to adjust temp will also affect humidity.
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Yes “in” inline duct is on the lowest possible point on the right side with the fan in the middle of the grow, exhaust is on the the top upper left. Both have inline fans. This am the temp was 86 and humidity 50. I also turn the 750cfm ceiling exhaust fan for 16 hours when the light is on without any change. Tonight I will try the frozen 2L frozen water trick to see if that will last and lower the temp, 4L if it doesn’t. I even found (and ordered) a duct register that would fit perfectly to direct all cool air to the grow. Further checking revealed I would be unable to open the door enough for me to get in/out of the room with flange centered above the register. Bottom line the floor register is too close to the door, order canx.
Thanks for taking me under your wing(s) guys. I’ll keep ya posted.
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I haven’t used any nutes and am ready to start cal/mag for my 2 surviving seedlings. Should I be using nutes other than cal/mag? If so, what type and what dose? The cal/mag recommends 5ml(1tsp) per gallon. Does the 1/4 strength apply to the cal/mag too or just the (other) nutes?
@Dorf I have 1/10 strength Big Bloom and 1/8 strength CalMag in a spray bottle for my seedlings in rockwool right now. I’m not going to assert that’s the right or only way to do it but my seedlings seem pretty happy. I’m terrified of giving them nute burn because they’re just spending all their energy developing roots. I added full strength Hydroguard to their water even though I know their roots arent big enough to reach yet. I want it to be safe for them the moment they hit it.
Here’s my oldest- she’s an Auto Gelato at exactly a week today.
I have her in a 5 gallon bucket with about 3.5 gallons of 5.8 ph water with 4 air stones - it’s absolutely bananas bubbling in there but they say there’s no such thing as too many air stones.
#2 is an Auto SuperSkunk, also 5 gal bucket and about 3.5 gal h20 - only 2 air stones in here- less insane bubbling but she doesn’t seem to mind.
#3 is a Lemon Tree reg seed, no clue what it’ll do. #2 and #3 are about 6 days old today, they started 24 hours after #1 because I was testing how long I really needed to soak the rockwool before it was viable. An hour seems to be plenty in case anyone wondered.
My tent is a 4x4 - temp is 76 today, two 100w LEDs at 25% and 75% power. I have a 6” fan exhausting but passive intake from a mesh vent. My humidity is low at 36% - I’m thinking if I can get a humidifier in here I can take the “domes” off my seeds and feel better.
I’ve got two lights going because I inherited a soil plant and I’m a fish outta water with the soil. 
@Dorf are you using the vending machine water still? I don’t know what they use for water in those things, but if they draw the water from town/city water, it could have chlorine or other things in it that could have an affect on the plants too.
How do the roots look on the seedlings? Imo you shouldn’t really push hardly any nutes except root zone nutes like great white, and Voodoo Juice and the like, until the roots/plants are big enough to make use of them. That being said, I started my clones in an Aero cloner with clonex and Great white at very low doses, but when the roots were about 3 or 4 inches long, I gave them 1/8th strength nutes from the recommended start nutes. So the chart said 8ml/gal, I gave them 1ml/gal until I started seeing growth in both areas, then slowly increased to 1/4, now I’m in flower and using 3/8 strength nutes, and full strength root zone nutes(Voodoo Juice). They look pretty happy to me
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Unfortunately I have no experience yet with hydro seedlings, only clones. But I follow a similar technique for my seedlings too, being start with root nutes and cal mag at light doses, then slowly increase as the plant shows growth.
Wow! Great info, thanks for the pics! I use clay pebbles under and on the sides of 3" rockwool. I just germed a white widow and a bubblegum. I check the pH daily, add 2tsps of H2O2 to a 3.5gall bucket every 5 days. and will start cal/mag at 1/8 (1/8tsp/gall). Still trying to bring temp down by different means, looks like lowering the house temp during the 16hrs is the most viable, more on that later
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OK. Starting today I change the reservoir water weekly. I started cal/mag nutes at 1/8t/gall. I didn’t sanitize the buckets w/bleach only cleaned w/anti-bacterial liquid dish detergent. I’m still working on the temp issue short of lowering the house temp at night. I’ve ordered FF Bloom and will start that at 1/10 strength. I raised the light from 12" TO 24". I sprayed the roots w/2parts H2O to 1part H2O2. I no longer add 2t of H2O2 to the water. I ordered Hydroguard as I see slimey floaters in the reservoir. Here’s some pics of the grow, they look damaged. Tips of leaves are brown, leaves turn downward and the nice green is faded. Looks like light was too close, too much heat?
@Dorf what do your roots look like? 3” rockwool feels large to me, but I can’t verify whether that’s a standard or not. I don’t think it’s time to back off on the light. Can we get better shots of the leaves? It might help diagnose where the problem is.
ps - I hear hydroguard is the cure for weird water if a good clean isn’t doing it, so you’re already on the right track.
Here’s the photos you requested as of this writing. Keep in mind I changed the water 24 hrs ago, added cal/mag (1/8t/gall), sprayed the roots in 1pt h2o2/2pts h2o, pH adjusted to 5.8/6.0 from 6.8. Waiting for my bloom and hydoguard. Today I raised the light from 24" to 39". Last night I lowered the house temp for 16 hours from 80 to 78 and may have to lower it to 76 or 77.
I believe there’s a light at the end of this tunnel, just haven’t seen it yet, thanks again for all your input
@Dorf Why are you wanting to raise your lights? They already look super stretched. Have you transitioned to something more powerful than your 100w? If not, I’d be moving the light closer, not further.
I’m only as educated as much as I’ve read, I’m still just anxiously watching my own seedlings, but those leaves are telling me they’re starving, not burning. Remember that your rockwool has absolutely no nutritional value for your seedlings, and the cotyledons are all used up.
Possibly someone else with a better eye can tell what’s going on from those leaves. @Myfriendis410 @Knowledgegrab28 @Member420 @OldSkool
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@Dorf, wow! I see you have some babies. Nice start! I would transplant them in a 6” soil pot, cover up a lot of the stock. Bring the down to 18” give them recharge, grow, and I use 1 tbsp, of molasses and those babies grow. 
To me something is going on, they look 
like the those babies need some light, look at this pic, hope this helps you with your grow, good luck with your grow, and happy growing. 
Just FYI, my Super Lemon Mac, and Sour Diesel is already 2 1/2 ft tall, and almost ready to transplant in the 5 gallon pot, veg them babies for about 6/7 weeks.
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I lowered the house temp to 78 for 16 hrs, the grow is still 84-85. Exhaust is on a timer for 16hrs, bottom line the temp is the grow is still too high. What if I opened the tent “door” during lights on? I believe it would drop the temp considerably but would this impair growth during vege? btw - what type and size pots are you using for your seedlings? More importantly why?
Does the tent have the ability to open more vents to increase the volume of cooler air going into the tent. I had to do this during my last grow. Also, having enough air circulation makes a huge difference. This was my last setup:
Small 8 inch circulating desk fan angled up under the canopy to push cool air up from the vent into the canopy, then a couple on opposite corners 4 and 6 inch not oscillating. Evened out the temp much better. This was a winter grow and I needed to heat it up, but similar concept of even distribution of air.
Very nice! So you’re saying I should be using my (purple) vege light instead of the (blue) seedling lights? Yesterday I lowered it to 24" (from 36") and have lowered it to 18" as of this writing. The only way I can get more (cool) air in/out is to open the front panel of the grow
during the light on stage. I have 2- 195 cfm fans. The air in fan is on 24/7. The exhaust is on when the light is on. Also a 16" oscillating fan on 4hrs/day. What I can do is open the front panel (“door”) to the grow to allow the cool air from the room into the grow, thoughts?
fyi - looks like the leaves are turning upward after only 24 hrs? pH jumps from 6.0-6.1 to 7.8 in 24 hrs (still waiting on hydroguard). I lowered the house temp to 77 which yielded a grow temp of 82.