Heat Stunting Babies?

[oregonhydro]

Hello all,

Ive been around weed for as long as I can remember but this is my first grow fully by myself, and my first time posting on this site
I learned a lot about growing on this site 5 or 6 years ago, but when i finally went at it recently,
i was surprised that i'd retained no information and have had to re learn everything.

Anyway I've launched into it, have a 4x4 insulated room in a room situation with 4 seedlings in 2x bubbleponic dwc totes.
All 8 seedlings i planted sprouted (Rapid Rooter, 2x LED veg bulb w/ hood) but only 4 made it to DWC, 2 OG Kush and 2 Zkittlez, I believe due to newb overwatering & insufficient light ( never used RR or LED bulbs) - on 4th day from sprout, removed from RR, rootrs were around 3" and i kept the main stem in tact at the least during transplant to 6" netpot.
2 OG Kush and 2 Zkittlez.

Even with the LED Bulbs my room was around 78.
Surrounding room is a garage that gets hot during day, can get it down to 70 minimum even at night. I did get a swamp cooler as I thought, what is the cheapest way I can cool down a whole garage ( only ventillation is two 4x12 ports right next to eachother, though i did put a computer fan in one) ?but $150 later i've got no difference but better humidity.

Then I decided it was a problem with my ventilation, though i felt plenty of airflow ( 2x 18" fan inside, 4" near bottom inlet and 6" outlet both with decent fans), i still bought two more fans to chain onto my inlet/ outlet. Since doing this, it seems my temps have become even more distant (10-12 degrees above surrounding room temperature). This is exteremely frustrating as it seems ive spent time and effort on something that did the opposite of my intention.

One seedling ( though it was the weakest from the get) has started to wilt severely as temps have been getting to 89-90 since the new fan install. They are perfectly healthy other than some potential White Powdery Mildew I've been spraying with baking soda/ soap solution. no clue if helping or not.

I only have a 600w MH air cooled 435 cfm extractor + 200 cfm booster n 150cfm intake. and has been turned no higher than 250W (ive tried but temps soar)
Keeping ice packs in dwc totes changing every 8-12 hours.

My theories:

1. Mylar reflective film on all surfaces too efficient in heat reflectivity. It's white all behind the mylar floor walls and cieling so that may to a better job and get better use out of structural insulation.

2. Not enough intake (4" 150cfm fan built into wall not good enough), need to drill more holes through the walls.

3. Global warming is real

4. Need to somehow vent heat directly to outside environment. Only problem is, my only potential exhaust is right above my only intake.

5. Need to spend another grand on shit I didn't expect to need

6. I should have just bought a grow tent.

Pics are both OG Kush plants, one wilting possibly over watering or heat stress, and one with a sort of white stain on it. wont rinse off.

Thoughts?

 

[mpence]

Are your buckets completely filled all the way? Looks to be that way in the photos... If so drop it down so it's 1 inch below net pots and hand water till roots come out. My experience with seedlings in dwc is that they need time to develop a decent root system before being put into bigger buckets.

 

[mpence]

Also where is your thermometer placed?

 

[oregonhydro]

Are your buckets completely filled all the way? Looks to be that way in the photos... If so drop it down so it's 1 inch below net pots and hand water till roots come out. My experience with seedlings in dwc is that they need time to develop a decent root system before being put into bigger buckets.

My buckets are not filled all the way just enough for the solution to pump to roots, as i figured roots were too small to be completely submerged in solution already. Haven't seen any roots poke out from the bottom yet. On my first flush I think I'll re fill it to just below the pot.

I have multiple thermometers and very good ventilation, temps are only getting 2-3 degrees hotter than the overall room temp just below the light.

I've began to feel more so that my sole 4" intake is insufficient as I feel at least double the air flow from the exhaust as I do from the intake. I feel the pressure should be even higher on the 4" since it's smaller than the 6". Maybe just some filtered passive intakes would do a better job for vent.
Currently have swamp cooler right up against intake, seems to help.

I've purchased a portable AC to get temps and humidity down for flower.

I have been pumping the seedlings water 24/7 except for when I have been adding h202 water to fix pH's.

I'm also getting more ice packs as temps are getting up to 83 in the rez's.

 

[mpence]

My buckets are not filled all the way just enough for the solution to pump to roots, as i figured roots were too small to be completely submerged in solution already. Haven't seen any roots poke out from the bottom yet. On my first flush I think I'll re fill it to just below the pot.

I have multiple thermometers and very good ventilation, temps are only getting 2-3 degrees hotter than the overall room temp just below the light.

I've began to feel more so that my sole 4" intake is insufficient as I feel at least double the air flow from the exhaust as I do from the intake. I feel the pressure should be even higher on the 4" since it's smaller than the 6". Maybe just some filtered passive intakes would do a better job for vent.
Currently have swamp cooler right up against intake, seems to help.

I've purchased a portable AC to get temps and humidity down for flower.

I have been pumping the seedlings water 24/7 except for when I have been adding h202 water to fix pH's.

I'm also getting more ice packs as temps are getting up to 83 in the rez's.

Adding more intake holes is probably a good start to deal with the heat as is getting the hot air out of the room. How far away is your light? Also if your res temps are that high without ice you're going to have loads of trouble, perhaps consider a water chiller or another grow method. Disregarding temperature, to me the problem with your seedlings doesn't seem to be heat. I use to start seedlings in my Coco grow in temps pushing 90f and they were generally fine. Your seedlings look over/underwatered and since they're in water it's probably lack of oxygen/fuck all roots. I have a similar post on here with seedlings that did nothing for weeks because they were just too small to put into my system. No matter the water level, amount of air, temp, humidity etc they still grew extremely slowly/not at all. Ended up pulling them out and putting them in Coco pucks to get them going. For future grows leave them in the rapid rooters for longer and if you're going to transfer to hydroton, use smaller net pots so you aren't waiting as long for roots to show.

 

[oregonhydro]

Adding more intake holes is probably a good start to deal with the heat as is getting the hot air out of the room. How far away is your light? Also if your res temps are that high without ice you're going to have loads of trouble, perhaps consider a water chiller or another grow method. Disregarding temperature, to me the problem with your seedlings doesn't seem to be heat. I use to start seedlings in my Coco grow in temps pushing 90f and they were generally fine. Your seedlings look over/underwatered and since they're in water it's probably lack of oxygen/fuck all roots. I have a similar post on here with seedlings that did nothing for weeks because they were just too small to put into my system. No matter the water level, amount of air, temp, humidity etc they still grew extremely slowly/not at all. Ended up pulling them out and putting them in Coco pucks to get them going. For future grows leave them in the rapid rooters for longer and if you're going to transfer to hydroton, use smaller net pots so you aren't waiting as long for roots to show.

I've always been infatuated with hydroponics&DWC, but I definitely see coco as a great middle ground. Better taste, less potential problems with the ease of soil but control of hydro. My light is around 30" from the plants. Been having daytime start at 8pm so i dont have to fight the temperature so hard. The reason I'd thought the heat hurt my seedling is because it dropped heavily when temps rose to 92 for the first time. Perking up more now, trying to position drip better as to not hit the whole root & suffocate them like you said.

I didn't mention but I have been using botanicare's KIND Grow/Base nutes with Hydrogaurd & h202, aiming for the most sterile enviornment i can get as to not spark something bad in the res. I was considering using real grower's recharge to help the babies out a bit but I dont know if it would work with h202. Have added a small amount of humic acid as well as silica to help with the heat. PPM's around 400 ( 120 off the filtered tap ), aiming for 5.8-6.0 pH, plants seem happy there. You're likely right that I could have used smaller net pots, but I don't see how I'd have let them grow longer in the RR without damaging root system to the same degree I had to anyway. Coco or vermiculite may be a better sprouting media for my next grow.

 

[mpence]

I've always been infatuated with hydroponics&DWC, but I definitely see coco as a great middle ground. Better taste, less potential problems with the ease of soil but control of hydro. My light is around 30" from the plants. Been having daytime start at 8pm so i dont have to fight the temperature so hard. The reason I'd thought the heat hurt my seedling is because it dropped heavily when temps rose to 92 for the first time. Perking up more now, trying to position drip better as to not hit the whole root & suffocate them like you said.

I didn't mention but I have been using botanicare's KIND Grow/Base nutes with Hydrogaurd & h202, aiming for the most sterile enviornment i can get as to not spark something bad in the res. I was considering using real grower's recharge to help the babies out a bit but I dont know if it would work with h202. Have added a small amount of humic acid as well as silica to help with the heat. PPM's around 400 ( 120 off the filtered tap ), aiming for 5.8-6.0 pH, plants seem happy there. You're likely right that I could have used smaller net pots, but I don't see how I'd have let them grow longer in the RR without damaging root system to the same degree I had to anyway. Coco or vermiculite may be a better sprouting media for my next grow.

I only run sterile. To the best of my knowledge you can't run hydroguard (beneficial bacterial) with peroxide, it's one or the other. Pretty much anything organic and hydrogen peroxide don't mix.

 

[oregonhydro]

I only run sterile. To the best of my knowledge you can't run hydroguard (beneficial bacterial) with peroxide, it's one or the other. Pretty much anything organic and hydrogen peroxide don't mix.

I realized this after I posted. How dumb of me, wasting nutes. Didn't consider how Hydrogaurd worked. Sterile seems safer to me. But if done right, beneficial bacteria seem to be the ultimate way to grow. I'm likely going to stick to sterile unless I can get my Rez temps way down.

 

[mpence]

I realized this after I posted. How dumb of me, wasting nutes. Didn't consider how Hydrogaurd worked. Sterile seems safer to me. But if done right, beneficial bacteria seem to be the ultimate way to grow. I'm likely going to stick to sterile unless I can get my Rez temps way down.

Running sterile if you don't have a chiller is probably the best way. Every couple of days I had 5ml of peroxide and my temps occasionally get up to 75f. Haven't had any problems so far (touch wood)