Grow Room CO2 on a Timer

Using the timer method with CO2 tanks, what is the recommended cycle for boosting the levels? 4 times a day? 5 times a day? I have a 5x5 grow tent.

Answer: The answer to your CO2 question depends on several things. First, the volume of your grow room. You have only given me two dimensions of your grow room, 5' (long) and 5' (wide), which is enough to calculate area....but not enough information to figure out the volume of the space. To figure out the air volume of your garden, I would also need a third dimension (height).

The next factor that will affect my answer is how frequently you are running your exhaust cycles. Every time you exhaust your grow room (to keep the temperature from getting too high), you also exhaust all of the CO2 rich air. Therefore, each time you run an exhaust cycle, you need to follow it by running a CO2 cycle. How long you leave the CO2 on during this cycle is a math problem, requiring you to know the volume of the grow room, the flow rate that you have your CO2 regulator set to, and the level of CO2 supplementation you desire to bring your garden up to (such as 1,500 ppm or 2,000 ppm). On my Using CO2 page, I walk you through all of this step by step.

Having a lot of experience trying to grow things in small spaces under grow lights, I have a pretty good idea how this is going to go for you. You will set up your grow room and quickly realize that you need to keep your exhaust fan running all the time just to keep the space livable (but probably still too warm) for your plants. At that point, you will have two options....either add air conditioning and run the exhaust to cool your light completely separate from the the air in the rest of the grow room, or else release your CO2 constantly (but slowly) as you are exhausting the room constantly.

Adding air conditioning with the CO2 is the best option, but in reality you do have a third option. For gardens tucked into small spaces and constantly exhausting, I often recommend no CO2 supplementation. First, there is usually a temperature issue....if all of the plant growth factors are not kept ideal, than you will not even realize the benefits of adding CO2 when it comes to the weight of your harvest. No sense in spending all that extra money setting up a CO2 system if you are not going to realize substantial gains from the strategy.

Second, plant growth will only stop if the atmospheric CO2 levels drop below 250 ppm (normal levels in the atmosphere are about 400 ppm). If you are constantly exhausting the grow room and constantly bringing in fresh air to replace it, you will never have an issue with having too little CO2 in the air.

Read this carefully and follow the links, especially the one for my CO2 page (it has a great section on CO2 calculations and setting timers), and you will have all the answers you are looking for. Just for good measure, also check out the exhaust setup page to brush up on the best strategies for exhausting your grow room area. I hope this helps, and Happy Growing!

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(10 week update below)

Find out the cheapest and easiest ways to garden productively in this article.

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Epic Nutrient Change

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Homemade Cloner

And, regarding the cost of the nutrients....I experimented for about 3 years with making different compost teas and nutrient teas, but there is still a lot of expense $$$ associated with making high quality nutrient kelp meal, liquid seaweed, rock dust, bat guano, un-Sulfured molasses, worm castings. You can eliminate a lot of this expense by becoming an expert at making high-quality colloidal humus compost, and use your properly made compost as the basis of your hydroponic nutrient solution.

Unfortunately, I have been gardening for over 24 years and I have only just recently mastered this difficult skill....and even then, only because I happened to find a very easy to follow, high quality technique and decided to follow the instructions to the letter. I produced more high quality compost in just one week than I was able to use in a whole year! If you can master the technique, I highly recommend it. It is one of the top 3 things you can do to increase the productivity of your food production efforts, while at the same time decreasing the amount of effort required to grow all of your own food, and decreasing the total cost of operating your food production system.

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This solution is aquaponics. If you are serious about producing all of your own food and being self-sufficient, this is the ultimate solution for reducing expenses (as much as possible), reducing the total amount of work required, and maximizing the productivity of your gardening efforts. I have been gardening for over 24 years, and it is the perfect food production solution in my opinion.

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Besides mastering how to make high quality compost, learning aquaponics is one of the top 3 things you can do to increase your garden productivity, reduce your total costs, and reduce your total work. The product that I learned from is called Aquaponics4you. With all of my hydroponic gardening experience, the first time I came across the Aquaponics4you product I knew immediately that it was something very special! Place an aquaponics system outdoors and use the sun instead of grow lights, and you have reduced every garden expense to nearly ZERO!

The Same System/ 10 Weeks Later!

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