Building and Using a Co2 Generator

[JrayJ]

Thank you very much! I always read about CO2 bombing tanks, but never really knew how to go about it. Very informative posts.

I loved the youtube videos, now waiting for my next shipment of Omaha Steaks that my grandma loves to send me with the nice healthy bag of dry ice in the bottom. Can't wait to see my little girls eyes when she sees the gigantic white bubble form!

JrayJ

[davecalk]

Thanks JrayJ,

Glad that you enjoyed them. I thought the videos were kind of fun too.

[davecalk]

Examples of Uses for CO2



CO2 to Kill Bugs / Slugs In A Tank

Been there done that got the Tee shirt, plus lots of pictures.

CO2 to Euthanasia Amphibians / Reptiles

In our community there are differing opinions on whether CO2 is a humanely acceptable method for culling reptiles and amphibians. In researching for this article, I found that the American Veterinary Medical Association has published guidelines about euthanizing small animals. In the AVMA Guidelines on Euthanasia 2007, these Veterinary practitioners feel that the use of CO2 is an acceptable method to terminate Amphibians and reptiles.

Carbon dioxide—Amphibians,1 reptiles,1 and fish203-205 may be euthanized with CO2. Loss of consciousness develops rapidly, but exposure times required for euthanasia are prolonged. This technique is more effective in active species and those with less tendency to hold their breath. Page 20

Dart Frogs
Our frogs are not swimmers, but are of the active variety and therefore do not tend to fit into the “Hold their breath” category.

Tadpoles
Also they say that fish can be euthanized with CO2 so our tads should be able to be put down in this way as well. To do this I imagine that you would insert the line from the CO2 separator tank into the water of a deli cup, making sure that there is a good air space above the waterline of the cup so that the CO2 will be able to build up within the cup above the waterline as you bubble the CO2 into the water. Adding an air stone to the line so that the CO2 bubbles would be able to aerate and saturate the water would be helpful to speed along this process.

Appendix 1 under amphibians lists all of the acceptable methods of euthanasia.
Barbiturates, inhalant anesthetics (in appropriate species), CO2, CO, tricaine methane sulfonate (TMS, MS 222), benzocaine hydrochloride, double pithing

I believe that there are a couple of reasons that using CO2 is considered an acceptable method of euthanizing amphibians and reptiles even though some species of amphibians and reptiles can survive under severe oxygen depravation.

1. carbon dioxide is a potent central nervous system depressant and thus causes rapid unconsciousness and is an anesthetic. It therefore reduces an animal’s sensitivity to pain and can cause unconsciousness rather quickly.
   
   
2. Because low oxygen levels in many of these species is a natural state of being for the animal, (ie. When they are swimming.) Therefore the oxygen deprivation debt is not putting them in distress while they are being put down, it just takes a longer period of time for the animal to expire, to “croak” so to speak.

Suggested Reading:

American Veterinary Medical Association's Guidelines on Euthanasia This file is large and may take a bit of time to load.

Caudata Culture Articles - Euthanasia

Controversial Euthanasia Methods - Definitions, Policies And Guidelines

A Study on the Anesthetic Properties of Carbon Dioxide in the Rat




Euthanasia Chamber
Here are a couple of articles that discuss how to build and use an euthanasia chamber.

Small Animal Euthanasia at Home using Baking Soda & Vinegar

The Reptile Rack Knowledgebase / CO2 Chamber Using Compressed CO2 Gas



For our needs, a simple small Tupperware container with snap on / screw on lid would be a perfectly acceptable euthanasia chamber.



Make sure that the CO2 comes in at the top of the chamber and that there are oxygen evacuation holes drilled in the lid so that the oxygen can be pushed up and out of the holes allowing the air in the chamber to be replaced with CO2. The CO2 hose could be connected to the chamber with a – 3/8” x 1/4" Brass Male Rigid Pipe to Barb Fitting.




Euthanasia Chamber Procedures:

CO2 CHAMBER PROCEDURES and ASSURING DEATH FOLLOWING CO2 EUTHANASIA

Standard operating procedures (SOP) describing the different recognized methods for rodent euthanasia.

Both of these are aimed at putting down rodents, but the methods and procedures should be about the same for amphibians.


Using the Baking Soda Method & Euthanasia
If you choose to use the Baking Soda / Vinegar method of generating the CO2, you will need to experiment with the mixtures before you make any attempts to put a frog down. You do not want to generate CO2 too quickly, like we were doing when filling the tank. The CO2 flow rate should provide a balance between the time to unconsciousness and the adverseness of the noise and high-velocity air movement which can come from too-high of a flow rate. A fill rate of about 20% of the chamber’s volume per minute would be what is recommended.

CO2 to Kill Bugs & Slugs In A
Moss / Bug Gas Chamber

When we collect moss from the wild, we can kill the slugs and critters in the moss without concern of transferring slugs and millipedes to our tank. I just did this with a bunch of moss, and it was quick and easy.

CO2 to Kill Bugs & Slugs In A
Plastic Plant Bag Gas Chamber

Using a Plastic Grocery Bag you can create a Gas Chamber for an individual plant that you purchased, in order to gas the bugs before the plant is introduced to your tank.






This is the last installment that I have planned.

I was kind of inspired to do this when when someone posted their experience of using dry ice to try and kill bugs and the extreme cold completely toasted their plants.

I hope that you all enjoyed the article and find the information helpful.