# Learning to love the C02 bomb



## kimcmich (Jan 17, 2016)

Greetings,

I built a large orchid vivarium back in February and have been delighted with its progress.

The last few weeks however, I began to notice an increase an plant damage - especially the orchid flowers. I would wake up in the morning to find half-eaten flowers and chewed-down new fern fronds. 

I started patrolling the tank with a flashlight and was able to pick out a good 20 slugs over a couple of days. After that it became really hard to find any slugs but the plant damage continued. It was then that I finally saw a small earwig one morning and realized my pest issues extended beyond the Mollusca.

I read-up on caffeine as a Mollusc-icide but further research indicated that many of my plants (bromeliads and pleurothallid orchids) were themselves susceptible to caffeine poisoning - and the caffeine could persist after the treatment. Since I plan to eventually add thumbnails to this viv, that was a no-go.

The CO2 bomb was my next option. I rented a 20lb tank from a local welding supply; 20lbs of CO2 is ~175 cubic feet (enough to fill my 3x3x7 viv more than twice). I sealed the gaps and vents in the viv with blue tape and hung a tea-candle in the upper portion to serve as my CO2 indicator.

When I turned on the CO2 tank, I realized its output range was more limited than I expected (with a max of ~25 cubic feet per hour). Thus it took longer to fill the tank (and snuff out the candle) that I planned - but, given Boyles Law, I soon realized that ~25 CFH was the limit because the regulator quickly frosted-over at the flow-rate. I turned-down the flow and added an electric blanket over the regulator to help the frost issue as I let the tank fill up for good measure. Then I turned the CO2 down to a 1 CFH rate (to keep the CO2 up in the tank even if there were some small leaks) and left it that way until morning.

Soon after the tank was full, I saw a small slug (on a conveniently front-and-centered plant) that had stopped moving and had its eye-stalks contracted. That was a good sign so I went to bed with visions of Slug-free vivariums dancing in my head.

This morning I unsealed the viv and collected a few slugs and tiny snails I found - all of which were lifeless. In addition to the Molluscs, I also found several dead earwigs. For good measure I ventilated them well and put them in an observation glass with a bit of moisture to make sure recovery and resurrection did not happen. Several hours later the critters are all still un-moving (though the slug did flinch one or twice when I first exposed it to oxygen again).

So it looks like the CO2 bomb has done the trick - and I couldn't be happier. Death to the slugs!


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## roundfrog (Jan 27, 2016)

You may need to do it again, as the slugs probably have eggs, and once they hatch out, the problem will begin again. It does help the plants though, so I guess that's a plus.


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## kimcmich (Jan 17, 2016)

Yo roundfrog,

A second (and perhaps third) treatment is the plan - I should be able to get at least one more all-night treatment in with the tank before I need a refill.

After about 5 hours in oxygen, one of the snails revived - it was one I found at the very bottom of the viv so it may have been partially shielded from the anoxia by the air being coldest at the bottom of the viv. The small earwig has twitched a bit has not moved otherwise. The snail and slug I got from the upper area of the viv are both still motionless 

I'll likely run the gas for longer next time - it was going for about 10 hours this first run - to try and prevent any survivors like the snail...


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## roundfrog (Jan 27, 2016)

kimcmich said:


> Yo roundfrog,
> 
> A second (and perhaps third) treatment is the plan - I should be able to get at least one more all-night treatment in with the tank before I need a refill.
> 
> ...


pretty strange that a snail at the bottom survived, as the co2 is heavier and will fill the bottom first. Maybe some bleach is in order for snails and earwigs that have been caught with thievery of plant cells


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## kimcmich (Jan 17, 2016)

As I mentioned, the only explanation I have for the lower-down snail surviving is cold - the bottom of the tank is where the coldest CO2 would have settled (it was quite chilled coming out of the tank). The snail is such colder temps would have needed less oxygen and thus was able to hold out longer. I'm hoping another longer CO2 gassing - more like 14-16 hours - will take care of that.


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## Pubfiction (Feb 3, 2013)

I would definitely throw everything you have at multiple treatments I would look up the life cycle of slugs and earwigs and time you treatments to hit after eggs should have hatched. And after you think you have done it I would do another couple of treatments. I found that CO2 bombing just wasn't effective. You see death, you see progress but it does not seem to be able to fully eradicate problems. Which means you will keep treating. 

Actually unless someone pipes up I have not heard of any long term success cases in CO2 bombing.


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