challenging question about co2. need help !! (pics)

This is my 3rd grow and i have a question about co2. I used co2 in my previous grows but because of funds and laziness only during the vegging cycle. However this time i have it on during my flower cycle.

I have a large tank of co2 hooked up to a regulator that is on a timer to go off once every hour for 15 minutes. I wont go into details but i have my exhaust and intake set up on a timer to go off right before the c02 goes on.

I have a sun hut xxxl and i plan on doing a cycle. My strains are bubba kush and green crack. The way i want my cycle to work is similar to Al b's setup but with only 2 trays. so every 4 weeks i will harvest and then add another tray. (i have a vegging room to)

So right now i have one tray that has been in there flowering for 3 weeks. So i will be adding more plants next week in the other tray (tray number 2). So that way it is on a 4 week cycle.

So my question is if i have c02 on the whole time will it effect my plants in a bad way. because when tray number one is 6 weeks into flowering the other tray will be only 2 weeks into flowering and i have heard not to use co2 on the last 2 weeks of flowering because it promotes unwanted vegetative growth and no bud production. but on the other hand the plants that are 2 weeks (tray 2) into flowering will benefit hugely from the extra boost of c02.

So its ether c02 from day one of 12/12 till chop.
or no c02 at all during the flowering phase

thanks and i would like to hear lots of input and different opinions

here are some pics of my last grow. not the high yield that i would of liked but very potent buds. You got to love GREENCRACK!....
btw its not cush, green cush, or mango. if you dont like the name to bad! how would you feel if you created and breed a amazing top 10 strain and people renamed it because they didnt like the name.

I have co2 and noticed veg growth in the last two weeks...never heard it was coming from the co2 tho. Will definitely investigate!

I have a perpetual going too...and I use Co2 in the flowering room and it's always on......my buds still taste great even if the Co2 promotes vegetative growth the last 2 weeks which I was not aware of........

so i guess it is fine to use co2 all the way through the grow then. thanks for the replys and input

c02 in combination with water makes glucose, this is the source of the plants energy. now there is a few things to consider when using c02 like running a sealed room, if sealed you will need to supplement c02 on your own, if exhausting regularly due to heat and humidity, fresh air is needed to exchanges the old stale air that c02 has been used up in. but heres the real deal on c02 in high levels, you often hear of 1500ppm of c02, this amount of c02 will never be utilized unless temps reach above 85F. plants have what is called a stomata, this stomata closes under 2 circumstances, one is lights off and two is temps at around 90F, plant growth comes to a halt, with the injection of elevated amounts of c02 the stomata will open at these higher temps, c02 should only be used when running sealed rooms for odor and security reasons and for if you cannot control high heat. imagine you just ran at high speed and your tired and huffing and puffing, nostrels flaring, getting all the oxygen you can before passing out, now imagine before you pass out you grab an oxygen mask , this is like c02 injection at high temps when the stomata is wide open, so basically your plants will pass out of heat exhaustion if not for higher levels of c02. injecting c02 at standard grow room conditions is a waste of money, at a normal temp of say 77-80F the small amounts of c02 that comes in with a new exhaust cycle is more than adequate, in this instance a circulation fan is more than enough to blow c02 rich air around the leaves to replace spent air........so in summary you can turn your tanks off its

Been doing this for 30 plus years.First of all my12/12 is on at night when co2 is at natural max..Never use co2 during veg or first 3 weeks of flowering.Then use co2 tanks the last5 or 6 weeks to the max,especially the last 2 weeks. The most important factor is your strain. My strain likes co2 and 9 weeks . 5 1000 watt lights = 10 pounds per go. Other things like ice or home made bottles of co2 are crap.

I have a large room with a CO2 generator, I use one 20 pound BBQ tank a week. I keep my levels at 1500 to 1800 ppm and only use it for flowering. It is computer controled, fans, lights and CO2. I have never noticed any veg growth in the last 2 weeks in my plants. I would recomend you let it run and see for yourself. I have been using gas for 5 years and love it. I have yet to get 2 lbs but I am still learning after many, many years. I do get 1.5 all the time per 1000w and the odd time 1.75, organic.

Peace

Just traded my old big tube lights in on T5's, I use them to veg clones and found they are growing abot 30% faster, us old dogs take a while to learn new tricks, as long as you keep learning you get better.

Why All Plants Need CO2


The dry matter in a plant is 90% carbon, hydrogen, and oxygen. All the carbon has to come from the carbon dioxide (C02) in the air. CO2 molecules are only necessary during the light times. Plants do not need CO2 in the dark period, and in fact plants breathe out CO2 all the time, just as humans do. The slight difference is that in the light period, leaves use up their own CO2 to make sugars and so appear to breathe out only oxygen in the daytime. The more light available to a plant, the more CO2 it needs for photosynthesis. Experiments have shown that during photosynthesis, it takes about 1 a photons to make enough electrons to create sufficient energy to split one CO2 molecule into carbon (c) and oxygen (02) atoms and form a sugar. There are trillions of photons striking the plant leaves, so a grower must provide enough CO2 or else the photons will just bounce off the leaves without doing much. A plant in full Sunlight (about 5,000 lumens per square foot) could process about 2,000 PPM of CO2 if it was made available in a greenhouse. Outdoor CO2 is nowhere near that. Indoor gardens with the light level at 3,000 lumens per square foot need about 1,500 PPM of CO2 for the limited light. With the level at 1,000 lumens per square foot, only about 300 PPM of CO2 is required - which is less than ambient air (city air normally has 400 PPM of CO2), The lower the CO2 level, the more the air has to be kept moving past the leaves. Remember that it is the PAR value (not lumens) that indicates the plants' use of CO2 because the light that the leaves cannot sense is totally wasted and does not go down the photon funnel to be used for splitting CO2 into sugar.
How Much Carbon Dioxide Can Your Indoor Garden Use?

Experiments have shown that plants can handle up to 10,000 PPM of CO2 with no ill effects. At very high light densities, indoor plants have a maximum CO2 uptake of just over 2,000 PPM.
Light intensity increases with closer distance, so the CO2 level around plants needs to be increased respectively:
This is with maintaining all plant resources at MAXIMUM and at a temperature NOT EXCEEDING 30°C (86°F).
* Ambient CO2 in the cities is between 400-500 PPM.
* Ambient CO2 in the country is about 300 PPM.
Note: Any time your indoor garden temperature goes above 30°C (86°F), start shutting down the CO2

Thanks for the input. however i'm not sure if the previous post is accurate. woodsmaneh! you added a note at the end of your post stating that when temps exceed 86F to turn of the co2. I think what you meant is to turn on th co2 when temps exceed 86f.

morrisgreensburg: my set up is ran at night but i have no ac so my temps are around 88-92 at the canopy and around 80-87 in non direct light.
the temps fluctuate when my air intake comes on, which is direct air from outside. outside temps where i live now are between 60-70 degrees at night.
however when my intake goes on my c02 is off.


To everyone who replied, thanks your input has helped. ive decided to run c02 the whole time during flowering. I already have the equipment, its not expensive to fill and its a lot cheaper than using ac.

Also my plants are about 3 1/2 weeks into flowering and they look amazing, the easily can pass for a plant at week 5. They are bubba kush and blackberry kush so they might be a little more resistant to heat stress.

mite wanna run to home depot or lowes and get a $20 hepa filter and rig it up to your intake, you will get bugs and PM, this was my method for winters and i have been battling bugs and PM since. that is a nice tidbit about light distance, since the closer the bulb and the hotter it gets, it is like putting your foot down on the accelerator harder, the engine works harder therefore more c02...remember what i said about the marathon runner with flaring nostrels?

i didn't mention it my previous post but i already have a filter on my intake. your 100% right on Powdery mildew and bugs. I changed the filter after about a 6 weeks and the thing was filthy on the oustide and covered in bugs that had got sucked onto the filter and died. That all would have been passed into my grow room.

Thanks again. I like the analogy with the runner