# CO2 for plant growth...



## travisc (Mar 30, 2009)

I've been doing a little bit of looking around regarding the use of CO2 to increase plant growth. Being an avid homebrewer, I have several full 20lb CO2 tanks around my house. It also only costs me $6 to fill each tank which is about 75% less than the average cost. 

First of all, is it even worth it???? Would I place the plants in a large tank and introduce the CO2 that way? I do not have any frogs yet and don't plan on getting any for 6-8 months so the frogs danger wouldn't be an issue. 

Also, noticed one vendor here which treats their plants and moss for pests by using CO2. How effective is that? As effective as a bleach solution?

Found this just now....
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COMPRESSED, BOTTLED CO2:

This is the second most popular method of CO2 enrichment and provides fairly accurate, controlled results. Compressed CO2 comes in metal containers under high pressure. Small cylinders contain 20 lbs. of compressed CO and large tanks hold 50 lbs. Pressure ranges from 1600 pounds per square inch to 2200 PSI.

To enrich available CO with compressed gas, the following equipment is needed:

1. Tank of compressed CO2

2. Pressure regulator

3. Flow meter

4. Solenoid valve, (plastic or metal)

5. Short-interval 24 hr. timer capable of having an "on time" variable from one to 20 minutes.

6. Connecting tubing, fittings and adapters

PRESSURIZED CO2 ENRICHMENT SYSTEM ARRANGEMENT

This method allows for the injection of a controlled amount of CO2 into the growing area at a given interval of time. The pressure regulator reduces the compressed gas pressure from 2200 lbs./square inch to a more controllable amount (100 to 200 PSI) which the flow meter can handle. The flow meter will deliver so many cubic feet per minute of CO2 to the plants for the duration of time that the solenoid valve is opened. The timer controls the time of day and length of time that the solenoid valve is open.

To operate this CO enrichment system in our standard 8' X 8' X 8' grow room area, we want to add enough CO to increase the near depleted level of 200 PPM to 1500 PPM. We must then add 1300 PPM of CO2 to a volume of 512 cu. ft. We would like to do this in intervals of time relative to the natural air exchange rate (leakage rate) to keep the CO level near the 1500 PPM range.

Let's select an injection time interval (CO2 enrichment time) of every two hours. First, we must determine how many cubic feet of CO2 must be added to 512 cu. ft. of volume to increase our 200 PPM to 1500 PPM. To do this, multiply the room volume of 512 cu. ft. by .0013 (1300 PPM) to obtain 0.66 cu. ft. of CO2 that is needed. Set the regulator at 100 PSI and the flow meter at 20 CFH (Cubic Feet per Hour) or 0.33 cubic feet per minute. If we set our timer to stay on for two minutes every two hours, we will get the 0.66 cubic feet of additional CO we need to bring the CO level to the 1500 PPM optimum level needed.

Each pound of CO compressed gas contains approximately 8.7 cubic feet of CO gas at atmospheric pressure. Compressed CO2 costs around 50 cents/lb. at most supply houses. At that rate of 0.66 cu. ft. every two hours for 18 hours per day, this method will cost around 30 cents per day to operate. The timer should be set to deliver CO2 during the "on time" (daylight time) for which the lights are set. This is the only time the plants can use CO2; they do not use it when it's dark.

The compressed gas method of CO enrichment has the advantages of fairly precise control, readily available equipment ($150.00 to $300.00 average cost for an installation) and it does not add extra heat to the growing area. It also works well for small growing spaces and after initial equipment costs, is not expensive to operate.


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## R1ch13 (Apr 16, 2008)

I didn't read all the bumf you posted etc as I'm half asleep.

But the c02 injection is a big thing when it comes to planted Aquariums, you inject the c02 via a pressurized tank, reg, optional solenoid valve (shut off at night) then it gets diffused into the water column by the likes of a ceramic diffuser.

Ive heard of people using dry ice, in order to create c02 to gas out pest infested vivs, but I wouldnt go using it to try and increase/ improve plant growth.

I have in the past used c02 in my planted aquariums, which really does make a huge difference to Aquatic plants, but I cant even fathom right now how this would work in our dart frog tanks.

The fact that it can eradicate a terrarium of pests, means it can just as easily kill your frogs, hence Id keep away, even before the livestock are added.

Richie

P.S even the most challenging plants will grow amazingly with some good lighting, airflow and misting, hence I think the c02 would be more of an inconvenience than anything else.


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## LeoB (Dec 17, 2009)

The danger of using co2 in a terrarium WITH animals in it is the possibility of creating a co2 blanket in the terrarium deu to possible lack of air circulation. I wouldnt use it in a terrarium with animals because of the danger the animals could die of low oxigen. To start up a tarrarium and increase plant growth it should be no problem as long as there is enough ventilation. As soon you introduce life stock the animals will produce co2 as well and artificial co2 gift will not be needed at all! I used co2 in aquariums as well and mostly stopped it because off excessive plant growth wich made me cut the plants every week. I am to lazy for that and rather keep my plants slow growing so i have better controll.

Leo


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## carbonetc (Oct 13, 2008)

CO2 is so effective in planted aquariums because CO2 is FAR less available underwater than it is above. I forget the exact figure, but I believe it's ~10,000x less available (see Diana Walstad's "Ecology of the Planted Aquarium"). All aquatic plants are handicapped -- they've sacrificed CO2 availability for a new environmental niche. They're perpetually starved. Growth we see in CO2-injected aquariums is like nothing you'd see in nature.

Since terrestrial plants always have all the CO2 they need, I imagine you'd find it a challenge to give them any significant boost without killing all your inhabitants, but I can't speak from experience.


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## harrywitmore (Feb 9, 2004)

I think your problem in a planted terrarium will be controlling growth as opposed to creating it. Most terrariums become overgrown quickly with no help from extra CO2. I think you time would be better spent getting the lighting humidity, temperature and air movement to optimal levels first, I think then you will see there is no need to boost the available CO2 which as stated before is already pretty abundant.


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## JoshH (Feb 13, 2008)

But what about boosting growth if you are trying to grow plants out as fast as possible to use in vivs, sell, or for other purposes? What would be a achievable percentage of increased growth rate? For instance, I build tanks for customers. Could I effectively seal off that tank and give them more light and CO2 to get the tank grown in faster?


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## harrywitmore (Feb 9, 2004)

I have no idea but I still say if you actually work on getting the other conditions correct it may give you better results than adding CO2 but I have not tried it.


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## frogparty (Dec 27, 2007)

Yes Josh, I think you'd see a big difference. In the illicit plant industry, CO2 injection when done properly significantly affects yield, growth rate, etc. I would have to look at references, but I think the boost is somewhere around 15 percent for standard levels of CO2 percentage increase 

Plants can and will utilize many times more CO2 than is currently present in our atmosphere, and angiosperms initially evolved in a time period when our atmosphere was much higher in CO2 than it is today. 

I have never used it on viv plants: orchids, broms, etc. But I am willing to bet you'd see a marked increase in the growth of just about everything. 

I agree that optimizing the other factors involved would be more beneficial to plant growth, but Ive seen your plants and everything looks pretty damn good to me. iF you are looking for that extra little oomph, an d can find a cost effective way to introduce it to your growing environment, then why not? It can't hurt


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## james67 (Jun 28, 2008)

co2 can be effective on a large scale, but i dont see it being feasible for small tanks. if all other aspects of growth are already optimal then it can be well worth the investment(again on a larger scale). even with the equipment you listed there are some missing pieces..... the most expensive ones. the missing pieces are the controllers ($500-700). co2 controllers actually turn the solenoid on and off based on readings from a ppm meter to achieve a constant optimal co2 concentration, because if you are not effectively using your co2 then why even bother. they have been somewhat widely used in hydroponic gardens where some have reported production levels increasing 300% from accurately measured and controlled co2 supplementation.

james


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## frogparty (Dec 27, 2007)

agreed, the solenoid controller is a vital piece of that system. Im not really thinking of pumping it into vivs, but instead into a mini greenhouse type enclosure for those attempting to grow plants FOR vis bigger faster etc. If you can double the rate of growth and your turnover of product is such that you could benefit from that boost, then 700 bucks seems like a worthwhile investment. If not, then perhaps a more effective fertilizer regime would be more beneficial. 

In vivs frogs breathe O2 and expel CO2. Fungus also does as well, and so while there may not be the highly elevated levels you could achieve with a CO2 injector, I think theres still plenty. Also, since the CO2 would be heavier than the air, I think attempting to elevate viv levels would have an adverse effect on the microfauna as the heaviest levels would initially be ground level.

Where it might be beneficial would be in a situatuion where a custom viv was built, and sparsely planted initially to save cost. CO2 could be pumped into this viv along with quality water, and light to help speed the grow in phase, but pre introduction of microfauna. Once the denser growth desired was achieved, CO2 could be turned off, microfauna added...


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## d-prime (Sep 29, 2008)

I used dry ice to get rid of the slugs in my vivarium, which worked with the adults, but never repeated to get the next generation. This was all done with the frogs removed from the tank.

What i did is let the co2 from the dry ice sublime with hot water, and sealed the tank shut after the cloud of co2 reached the top (it is denser than O2 so it can displace it upwards.)

I left the tank sealed for 4 days, and then most of the slugs were dead. I let it air out for an hour with a fan running. I then put my frogs back in, misted, and was all set. 

My et fern shot out 8 new shoots overnight, mushrooms popped up from the substrate and driftwood and within a week, one of my plaurothalids bloomed.

Since dry ice is pure CO2, i had no concerns with chemicals, but i wouldnt use paintball tanks, fire extinguishers, or anything else.


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