New Grower Auto's and C02 Question-With pics of my setup

[derek420colorado]

Here is my setup, and quite honestly may become my Autoxtreme grow journal as well. My question is about c02 and temperature. I can configure my lights and cooling system 2 different ways.

The first way is how you see in the picture and I can control the temps in the room thru lots of air exchange as I have 2 440CFM fans for 2 1kw mh/hps digtal balast lights. I can go anywhere from 72 or so up to 78 with both fans bringing cold colorado air in thru a hole in the attic and out into another room.

The second is what I call my close loop system or c02 setup. I just hook up both fans to both lights and ducting up to the attic so it pulls from the attic over the lights and into the other room. With this I can stay under 85.

My question is for this Autoxtreme grow, that I am just waiting on my beans to arrive(1st set got intercepted by customs grrrrr), would it be better to run the first setup with the cooler temps or take all the air exhange out and run c02? Any help would be much appreciated!

 

[Muddy]

It really come down to how intent you are about running CO2. On your first setup you're actually running a bit to low on your temps. Ideally with HPS light you want to run around 80 - 82 degrees. So if you go that route you'll need to slow down or restrict your air exchange some to increase the temps a bit. If you go with the CO2, 85 is fine. CO2 is better utilized at slightly higher temperatures.

 

[derek420colorado]

Thanks for the info! Sorry in advance for the long post.

I have about 10 grows with DWC and soil and on my last grow(about 6 years ago) I started using c02 in the last 4 weeks of flowering and I THINK it helped but really have no way of knowing as it was only a couple plants and I had never grown that strain before. So I guess does c02 really do that much. Also what would you say a min and max temp range would be for using around 1300 PPM C02?

I can get it to be basically anything I want due to the cold cold air that comes in thru the attic. So if it is 85 or 86 and then it gets down to 60 or 65 at lights off will that cause stress.

So far from what I have read over the past few months is that with Auto's the main thing you want to avoid is stress of the plant in any type, this is also just a good rule of thumb I know duh don't stress your plants lol. However with Autos I have read that it can severly inhibit the growth if they are stressed is that correct? This seems right because its not like you can just Veg them longer as with photos to overcome any early stressors.

So will the added stress of having such a big temp swing contridict what the c02 would provide? Also do I HAVE to turn the lights off? I have gotten soooooo many different answers to this question(before I found AFN some say the plants need rest for X,Y and Z others say that it produces photosynthisis all the time blah blah blah. I am leaning towards going with a 24/0 regimin because I dont have to deal with light leaks and stressing the plant also there is no temp swing. Or at least that is what I am going to try first.

 

[Muddy]

CO2 is most effective during veg and early flower. Too much in late flowering can cause the buds to become fluffy. If you start at 1,500 ppm you can maintain that throughout the veg period, the first 6 weeks. After that, slowly lower it so by the time they are finished you're at about 700 - 800 ppm.

Temps that low may have an adverse effect on the plants. You might consider adding one of these to your setup: http://www.qcsupply.com/commercial-...mount-variable-speed-controller-110-volt.html. It will speed up or slow down your exhaust fan as needed to maintain the set temperature.

Autos are hardy little beasts. Yes, if they are stressed early on they can become stunted. But that usually occurs from hot soil, overfeeding, slow release nutrients and such. Autos only require about half the nutrients of photos and prefer soils which do not contain large amounts of amendments such as worm castings, guano or composted manure.

I run a 20/4 schedule. Most here either run that or 18/6. Yes, they can run on 24/0 but IMO that bit of rest does help them.

Check out the first link in my signature. I think it will answer a lot of your questions.

 

[derek420colorado]

Temps that low may have an adverse effect on the plants. You might consider adding one of these to your setup: http://www.qcsupply.com/commercial-...mount-variable-speed-controller-110-volt.html. It will speed up or slow down your exhaust fan as needed to maintain the set temperature.

I have a fan speed controller, it came with my grow package but I dont see how that will help combat the low temps as it turns the fan on when it is colder than 10 degrees of what the knob is set at, so when the lights are off it gets colder and with the intake coming in from the attic if I turn the fans on durning lights out it will make it colder. I can turn the speed down when the lights are on and make it warmer or colder that is how I have so much control over my temps in my room

That is why I kinda want to run it 24/0 so the low temps dont become an issue. I have run photos in veg for 24/0 that is just how I always did it, I think the more photosynthisis the more growth(that is just my opinion based on results I have obtained in the past) but I am totally new to autos.

 

[derek420colorado]

Also what nutes do you use? I have Huboldt master A and B and am going to get some Cal/mag and Al-ga-mic. OR I am contemplating using Dutch Pro's Hydro Auto Nutes the only thing I am afraid of is the portions. I have a feeling these are just lesser strength than photo nutes but if I do go with the Dutch Pro I will start at 1/4 or 1/2 strength. Have you seen anyone use these? I have seen a couple people say they are good

 

[Muddy]

I'm assuming your second option, the closed environment with CO2. On second thought, that controller might not be the best for that situation. While it would automatically maintain the set temperature it would also suck out the CO2. If you go with your first option, they I think it would be a good fit. You may need to put a small space heater in there for lights out.

 

[derek420colorado]

Ok so that brings me to my next question, when do I start using the c02? Do I need to wait for a full set of nodes or two so it can use the c02 or do I need to wait a little longer to wait for root development?

 

[Muddy]

As soon as they have their first true set of leaves they can start to benefit from it.

 

[derek420colorado]

Ok so now I have hooked up the fan speed controller and started messing with the settings( I had it on the wrong one) now I can precisly set the temperature by hooking the controller up to my exhaust fan.

The question I have now is about the air ventalation. If the air is getting exchanged about once every minute and half or so is that too often to effectively run a bottled c02 system?