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- #221
I can afford a new fan. I can pick one up at the hydro store today but their prices are pretty high so may opt to get one online. Suggestions, size and brand?
Weenmeoff's Inside Soil Alien Abduction Grow Journal
I went with an Ostberg 6" with a 6" Can filter and the flange that attached them together. I consulted with duggan, who's been an electrician for years. It's one of my best purchases, in my opinion, and ran me less than $250 total, shipped. Duggan tells me, running at 75% it should last me many, many years. I couldn't be happier.
I know ours is an apollo horticulture. We have many of them, but for our tent we used a 6" exhaust. Nis knows all the specs on them, but they did a good job in the tents
Our 6" fans are IPower that are 440 cfm. Our 8" fan is Apollo which is plastic and didnt realize it until we got it. But it is 770cfm. Our intake fans are 6" 250 cfm picked up at the hardware store. Intake fans need to be less than exhaust like dirt said. Negative pressure ensures that odors go where needed instead of being pushed out of the tent where you don't want it. Also it ensures proper air exchange. You need that since once the plants use up all of the co2 and you keep recirculating the same air, they have little to no food.
While on the subject of co2, if you introduce more co2 (normal air is 200 ppm and can supplement up to 1200 to 1400 ppm) they are more able to enjoy the higher temps. Just some food for thought.
While on the subject of co2, if you introduce more co2 (normal air is 200 ppm and can supplement up to 1200 to 1400 ppm) they are more able to enjoy the higher temps. Just some food for thought.
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- #225
Thanks all! I will research these fans online. Do you think my 160 CFM is good for the inlet?
Also, any suggestions for CO2 systems?
Also, any suggestions for CO2 systems?
That fan would be sufficient for the intake yes. As for co2, if you want to go cheap you can make one out of a gallon jug filled half way and put a package of yeast in there, cut a hole in the cap and run tubing into it but not in the water. Put the other end of the tubing into a bottle of water to act as a bubbler. Then whammo you have co2. Just replace half of the water once a week. Don't have to add more yeast since more is created.
Or if you want to spend some money, you can buy multiple products that will achieve better results and more controlled. I am half tempted to get a 100 lb bottle and a controller and supplement our rooms with co2. That'll be in a couple months or so down the road. Hope this helps.
Thoughts on co2
If you have a lot of fresh air, the fresh air has co2
If you have a lot of fresh air, the exhaust fan removes the co2.
I have an 8x4' flowering room with a 7' ceiling that holds 32x7=224 cubic feet of air. This means my 270cfm fan removes a room full of air in about a minute.
With a large enough exhaust fan, most of the co2 you add to the air will be gone in a minute. Most of the air conditioning cooling you add to the room will be gone in a minute. Most of the heat added by your lights will be gone in a minute.
Without spending money on co2 controllers that coordinate with fan controllers, I won't spend money on co2 or A/C because I would just be adding co2 and A/C to the outside world.
The A/C is a tough call I don't have to make because my basement air temps are always in the 50s or 60s. If you have 80 degree ambient air, I don't see how you can ever get your flower area much under 90 unless you add A/C.
If you are experiencing heat issues, you need to be running your lights during the coldest part of the day with lights out during the hotest parts of the day.
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My 2 cents. If I am wrong, please tell me why so I don't spread errors.
If you have a lot of fresh air, the fresh air has co2
If you have a lot of fresh air, the exhaust fan removes the co2.
I have an 8x4' flowering room with a 7' ceiling that holds 32x7=224 cubic feet of air. This means my 270cfm fan removes a room full of air in about a minute.
With a large enough exhaust fan, most of the co2 you add to the air will be gone in a minute. Most of the air conditioning cooling you add to the room will be gone in a minute. Most of the heat added by your lights will be gone in a minute.
Without spending money on co2 controllers that coordinate with fan controllers, I won't spend money on co2 or A/C because I would just be adding co2 and A/C to the outside world.
The A/C is a tough call I don't have to make because my basement air temps are always in the 50s or 60s. If you have 80 degree ambient air, I don't see how you can ever get your flower area much under 90 unless you add A/C.
If you are experiencing heat issues, you need to be running your lights during the coldest part of the day with lights out during the hotest parts of the day.
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My 2 cents. If I am wrong, please tell me why so I don't spread errors.
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- #228
Thanks Nis! I'll try the cheap version for now.
Thanks Rad! The CO2 set up with controls sounds complicated and expensive. I'll need to do more research but for now I will try the cheap route that Nis suggested.
When you say with a large enough fan, the co2 you add would be gone in a minute, but wouldn't it be replaced with more at the same time...?
Still no concrete signs of sex yet. One of the clones now has alternate nodes though.
Thanks Rad! The CO2 set up with controls sounds complicated and expensive. I'll need to do more research but for now I will try the cheap route that Nis suggested.
When you say with a large enough fan, the co2 you add would be gone in a minute, but wouldn't it be replaced with more at the same time...?
Still no concrete signs of sex yet. One of the clones now has alternate nodes though.
Well, yes, there will be more co2 added each minute, more A/C added cooling each minute, and more heat from LEDs extracted each minute.
Think for a minute about about A/C in a car.
When you want to take full advantage of the cooling, you punch on the recirculate button- it works but the air starts feeling stale. Your body craves the oxygen from the outer air because in a confined space you are using up the oxygen in the air. This is similar to your plants locked in a room with no outside air wanting more co2 - this is the time in which you want to add co2.
When you turn off the recirculate in your closed car, the A/C is a little less effective but the air is better. The amount of air moved in your car is now similar to a bathroom fan. There is enough air flow to eliminate odors and keep the air somewhat fresh. The A/C still works well. Supplementing co2 would still be good for plants. If you only have a 30-50 CFM fan in your tent, this would be similar.
But A/C with the windows up is still too hot when you first get into a car that has been sitting in the baking sun. When you want to cool down fast you roll down at least one window on each side of the car. Driving at 30 mph your car cools down from 130F to ambient air temperatures in under a minute. For that first minute A/C doesn't matter, the goal is to get that overheated air out of the car as soon as possible. There is plenty of oxygen to breathe and the air is as fresh and cool as outside.
In my opinion, running hundreds of watts of light in a flowering room is like that overheating dashboard in a car, you often need to push around A LOT of air to cool things down. Once you are pushing that much air, there is no need to add oxygen or co2. There is fresh air to breathe every second. When the lights are burning bright, the co2 just gets flushed outside by the moving air.
The time when additional co2 has time to accumulate in the air is the time when the exhaust fan is off. If the exhaust fan is off and the lights are on, adding co2 is beneficial to your plants. But the largest length of time when the exhaust fan is off, the lights are also off. During the hours of darkness, plants breathe differently: plants breathe in oxygen and breathe out co2. Adding co2 with the lights out makes it harder for plants to do their night time breathing. For co2 to be beneficial to the plants you really need the controllers that add co2 only with exhaust fan off and lights on. Without the controllers, you are spending your money to do some good in the daytime and mostly bad at night.
If you have your exhaust fan removing air from ONLY around your lights and not air from the room, then you can benefit from added co2 without an expensive controller, but still only when the lights are on. You still want your co2 generator to turn off and on when your lights turn off and on. A chemically reacting container won't do that unless it has a way to be opened and closed. The expense of doing it right is why I don't add extra co2.
I saw that in your last photo. Good stuff happening
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- #230
Damn Rad that was detailed! Based on your comments I will hold of on adding extra CO2 since my fan goes off when the lights do.
I have a fan and controller on the way which should help the heat problem which really isn't that bad yet. It got up to 90 a couple times but is usually around 86 with lights on.
I have a fan and controller on the way which should help the heat problem which really isn't that bad yet. It got up to 90 a couple times but is usually around 86 with lights on.
86 doesn't sound bad . I usually do 78-82 as a high temp. I think this was based on Jorge Cervantes 75-85, who remembers ?
Sorry if the detailed post sounded like a rant. I was typing my thoughts in detail to see if they still made sense when spelled out. It might not be right, it's just how I think of things.
Sorry if the detailed post sounded like a rant. I was typing my thoughts in detail to see if they still made sense when spelled out. It might not be right, it's just how I think of things.
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- #232
86 doesn't sound bad . I usually do 78-82 as a high temp. I think this was based on Jorge Cervantes 75-85, who remembers ?
Sorry if the detailed post sounded like a rant. I was typing my thoughts in detail to see if they still made sense when spelled out. It might not be right, it's just how I think of things.
I pretty much understood your point and appreciate your help!
Demon42069
Well-Known Member
sounds right to me, from what I read you need a light exhaust that doesn't intake or exhaust inside the tent and then a separate carbon filter exhaust that only runs when co2 is off. good info 
Usually co2 is added just before lights out and lights on. But if you have a controller it doesn't put out co2 when the exhaust is on. I've looked into those controllers for our setup, but for your tent I wouldn't worry about it.
Your clones should be close to showing sex. Couple days at the most.
Your clones should be close to showing sex. Couple days at the most.
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- #235
I sure hope so. #1 the giant runt will probably be a male, the growth at the nodes looks like crab claws. The other 2 should be females, it seems like tiny pistils are showing. I went with the i Power 442 CFM which will be installed today. I hope that solves my heat issues.
Thanks for stopping by demon!
Thanks for stopping by demon!
Oh it will help. That's the fan we have and it moves a lot of air. As long as you exhaust to where you are not pulling your fresh intake air from then it'll be night and day difference. Did you decide to run passive intake (pulling in air through the vents without fans) or are you going to use the lesser cfm fan for intake?
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- #237
I will use my 160 CFM for intake. I also have a speed controller on the way. Should have the fans on same times as lights so they're not running when the lights are off?
Demon42069
Well-Known Member
thanks, looking good.
intake fan is the way I went. helps keeps bugs out and let's you intake from an ac vent if needed.
I always left the exhaust fan on but had the intake on a timer so it was off when the lights were off. In veg we had the fan turn off 30 minutes after lights went out and 30 mins before.
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- #240
I got my fan and damn this thing is a monster! I had no idea it was going to be this big. Correct me if I'm wrong but to create negative pressure, once both fans are hooked up and running and tent is closed, I want to find the spot on the speed controller for the exhaust fan where the tent walls are sucking in slightly? They're sleeping now but I'll hook everything up later and let you know how it's working.