Anyone using CO2?

[Jim Toomey]

Hello all,
Anyone using CO2?

Please describe your experiences; your setup and equipment you use or recommend.

Pitfalls to avoid?

I am thinking of using bottled CO2 in my hobby-house (500 SQ FT) hooked up to a monitor/controller (maybe C.A.P. brand) set to 1500 ppm.

I am thinking bottled CO2 would be better than the propane CO2 generators. While I have propane for my heater available, I am concerned about the added heat buildup in the summer that will just get vented out every-time the exhaust fans kick in (and they would kick in much more frequently in my small hobby-house due to the heat from the flames).
I am interested to know after the expense would you do it again?
Are the results significant enough?
Thanks for your time,
AHAB

 

[Ernie]

Interesting. I'm curious to hear some responses. I have used yeast CO2 generators in planted aquariums, but haven't gone that extra mile for land plants.

-Ernie

 

[Kyle]

A guy in my OS used compressed CO2 for cooling. Not sure of the details.

Kyle

 

[Rick]

I don't use it in my GH but at work we use it to regulate water pH in toxicity tests.

We use bottled CO2 in conjunction with a monitor/controller.

The setup is in a relatively well sealed room about 8X8X8. At concentrations appropriate for horticulture use the 25 lb bottle will last at least a month in this room.

In water with normal buffering content 800 to 1500 ppm will regulate pH effectively. But I really can't give you any hands on info on how well orchids will grow in this setup.

 

[Jim Toomey]

I recently had a small greenhouse built (for paph's of course) and now I'm looking into the limiting factors of plant growth. I'm trying to tie in information from all types of agriculture.

From what I've read CO2 is one of the limiting factors in the plants growth that I have not addressed.
So I'm trying to find out if anyone else has had success with adding CO2 to their growing space. I am looking to see if it is viable, practical, and cost effective.
Thanks,
AHAB
(nickname from the slightly obsessive compulsive captain in Moby Dick)

 

[Candace]

I would think you'd have to have a pretty airtight g.h. for CO2 release. If you've got an evap. cooler, shutters, door gaps etc. it would let the CO2 right out.

 

[Ernie]

I recall Russ Vernon saying Eric Young Orchid Foundation uses CO2 generators?

-Ernie

 

[cnycharles]

one problem with co2 treatment with plants that are long-term growth is that research I don't have personally available is that when a plant is initially subjected to co2, it will grow more (very general statement, more involved). after a point, the plants' growth rate will slow to before as it gets 'used' to the higher gas content. if you are growing plants quickly and turning them over it might be a good idea if you can seal things up. when the co2 is being released you won't be able to vent or exchange internal/external gases. we have co2 generators at work (huge propane burners) and sensors for co2 levels that are useless for that use because of the need to keep things sealed when the gas is released. we use them for backup heat, but that's it.

there is more science to the explanation, but I haven't read or heard it for a number of years and haven't retained much of the info. I don't think it is really like an increase of fertilizer where you could have continued growth with more (as long as the plant is able to take it up and other environmental conditions are good, warm and humid with adequate moisture etc) that continues, growth will rise to a point but then settle and not increase any more.

I also think I remember that the best time to try it is during the night, but other than it being a time when the need for venting might be lower, I don't remember the reasons

 

[Rick]

I also think I remember that the best time to try it is during the night, but other than it being a time when the need for venting might be lower, I don't remember the reasons

That's not very intuitive since plants generate CO2 at night when there is no light, but need it during photosynthesis.

Most of the applications I've heard about were aquarium use, which is a much more sealed/closed system than most terrestrial and GH systems.

When I was purchasing the system for our lab, the vendor website had some how too for GH use testimonials and such. I bet you could get some results pretty fast by googling.

 

[Ray]

There is a gentleman posting at the OrchidSource who is a believer. He has a CO2 sensor and automated regulator, so just like heat, it is possible to compensate for greenhouse losses fairly easily.

Assuming I can find a decent local source for bottled gas, I am planning on trying it myself. The much-less-expensive controller I will use is an on/off timer, set based upon calculations, but with some inexpensive testing, it can be "tuned" reasonably well.

I haven't given it a lot of thought, but I'm not sure I "buy" the bit about plants "getting used to" the higher gas content. It seems to me that plant growth is sort-of like a car engine - given enough fuel and air, it will run faster and faster, up to some design limit. That limit is genetics, and the "fuel" is likely the combination of chemical raw materials and light. If we increase only one component, I could picture that there might be an initial "surge", but then it simply could not keep up. Increase everything appropriately, and we might see "another gear" kick in.

 

[Inverness]

CO2 usage

Here's some info that may answer many of the questions.

www.omafra.gov.on.ca/english/crops/facts/00-077.htm

In commercial situations CO2 is normally only used when the greenhouse is closed up. Once the space requires venting or cooling the benefits disappear and costs skyrocket.

Ken B.

 

[charlie c]

Here's some info that may answer many of the questions.

www.omafra.gov.on.ca/english/crops/facts/00-077.htm

In commercial situations CO2 is normally only used when the greenhouse is closed up. Once the space requires venting or cooling the benefits disappear and costs skyrocket.

Ken B.

Thanks Ken.
An interesting read. And an informative site.

charlie c

 

[Rick]

There is a gentleman posting at the OrchidSource who is a believer. He has a CO2 sensor and automated regulator, so just like heat, it is possible to compensate for greenhouse losses fairly easily.

Assuming I can find a decent local source for bottled gas, I am planning on trying it myself. The much-less-expensive controller I will use is an on/off timer, set based upon calculations, but with some inexpensive testing, it can be "tuned" reasonably well.

Ray I've been amazed as to how little gas from the bottle will launch the CO2 concentration through the roof. I wouldn't administer by timer without any way to monitor and calibrate the CO2 concentration you want. In our small test room, the controler will pop on and off every few hours (depending on traffic in and out of the room), but it is generally only on for 30 seconds to a minute at a time.

We buy our gas from a company called Nexair, and I think they have branches all around the country. They supply all types of gases to industry and medical needs.

 

[Jim Toomey]

Hey all,
Thank you very much for all of the feedback!
I read the article from Inverness, it really helps firm up that using CO2 is viable.
The controllers are expensive though, even on ebay they are around $500.
So I am still looking for an accurate CO2 monitor controller.

Any other pro's or con's?
Thanks,
AHAB

 

[Inverness]

CO2 Revisited

Another comment on the CO2 usage. Unless all other cultural parameters are near optimum, there may not be as much benefit from elevated CO2 levels as expected. Also, plants that tend to grow rapidly, such as those that reach full flowering/vegetative maturity in as little as ten to twelve weeks (mums, points, lettuce) will often show good response to higher levels of CO2. Plants such as orchids, cacti, azaleas and others may well receive added benefit; but it won't be as of a striking nature. Saving a week in twelve is significant, saving a week or two over several years doesn't have the same appeal. It's possible that paring CO2 with eighteen hour days as provided by HID lighting and a uniformly warm growing temperature could induce a better growth response, but you'd have to decide how accelerated growth response compared with overall cost to achieve it.

Ken Brewer

 

[Rick]

The system I use in our lab can be checked out at:


www.CAPcontrollers.com

we got the CO2 reulator 1 and the monitor/controller ppm3

 

[Ray]

Rick,

The timer/controller I'm talking about has a regulator and flow meter, in addition to the timer-controlled solenoid.

The concept being that you calculate a flow needed for the desired level, and the timer opens the valve every 15 minutes for a set time period. There is a test kit to allow you to fine tune the settings. While not as precise or stable as the other systems, it's a lot cheaper!

 

[Rick]

I understand Ray.

There's allot of tolerance in the system as far as the amount of CO2 that would be considered dangerous or an overdose, so you shouldn't have a safety issue if your calculations are wrong.

You've been dosing all kinds of stuff for years now, so I can't imagine you'd have any problems figuring this out.

If your leakage (or plant uptake) is more (or less) than anticipated you wouldn't have any way of optimizing your dose. Kind of like driving a car blindfolded with only one speed set on the gas petal.

If you have a spare pH meter, and an aquarium air pump handy you can get a rough idea of how much CO2 is in the air, by how much the pH of a cup of water is depressed as the gas goes into the GH.

In our lab a cup of lab water with moderate hardness and alkalinity has a static background pH of about 8.1. Ambient CO2 about 500-600 ppm. When we pump the CO2 to 1500 ppm the pH will drop to about 7 - 7.2.

Before we got the controller, this is how we used to control CO2.

 

[Ray]

Why is your ambient CO2 level so high? 300-400 is normal.

 

[Rick]

Why is your ambient CO2 level so high? 300-400 is normal.

Small closed room and people breathing.

It's kind of interesting how little it takes to make the meter jump up.