dry ice

[Dr.Danio]

for those of you who don't know, dry ice is awesome. If you didn't know that then you probably also don't know that its frozen solid CO². I work in a molecular biology lab and we get shipments a few times a week that are packed in dry ice. Besides a few thousand Zebra Danios in the Matrix we have a nice little 10 gallon 'aesthetic' tank with some cheapo walmart aponogeton and such that grow fine with about 8 hours of indirect flourescent light from the cieling. In the process of playing around with the dry ice (flash freezing things, making big fog clouds, general mad scientist stuff) we put a chunk in the tank. next day, BAM! lots of growth. so this week i brought some home to my planted 35. BAM! lots of growth. The only drawback is that its not the safest bet for CO² as its really cold and can be a tad stressful on the fish. but nonetheless it works like crazy and (for me at least) is a free CO² injection system.

SO, if you don't normally get huge boxes in the mail like I do you can probably get it for free somewhere else. Ice cream distributors use it alot to ship it to stores, especially places like baskin robins or stores that don't make thier own ice cream. some meat pakers use it too, but not that often. also, you could try your local university or laboratory to see if they have any. most of the time places will just give it away as it requires a -80 C temp if you're going to keep it around for longer than a day. try the "its for a school project" if your a kid. if you have kids, ditto. if you're in that ackward age between the two, try it anyway. and if you try it, just a small chunk will do, like a pack of lifesavers size chunk will be more than enough for a 20 gallon. just make sure your heaters on....

thats just my random contribution for the day.

 

[fishfreek]

Do you have any 'safe handling' procedures you can give.

Also given its frozen co2 it would be good ot not add to much as you could hurt more than it helps.

 

[Guest]

Ever test your ph before, during, and after putting in dry ice? I'd love to see the results, but I'm betting on massive ph drops from doing that.

 

[Mr Burns]

very interesting, but i think more extensive testing a data is needed... i've never played with dry ice, but will it sink or just float like a normal ice cube? i think there's a restaurant across from the university that i can get dry ice...might be worth a shot when i'm setting up my new tank (before fish are added)

 

[Dr.Danio]

as for safety: its really freaking cold, don't hold it in your bare hands for too long. otherwise its not dangerous besides its temperature, I put it in warm soda to cool it down quick.

as for water chemistry, it will do absolutely nothing different than adding CO² any other way. if you have a reactor with a steady bubble rate you're just adding it more slowly, drop the ice in (it sinks mr. burns) and it bubbles like mad until its gone. all you're doing is adding one big dose of CO². it will disperse very quickly, so any pH change would be just as fleeting. next time I do it i will keep track. actually, i'm going to go downstairs to the lab (in my office now...yes at 6pm on a friday) and run a quick test on the 10 gallon. i'll get you exact figures in a half hour.

I've been using it after I do a water change, because I add plant food so all kinds of nutrients are available, and I toss it in in the morning (I have to bring home like a gallon to have a handful left after a night) because the plants only use CO² with light. Its not so much to have constant steady high growth, but more to supplement and give a little kick to the plants growth. as a testament for why i'm telling you all about it, I've had 4 clumps of Green Mondo for 5 months and all they've done is grow diatoms for my ottos to eat. I did this twice and now they've each got huge buds of 20-30 new blades growing. all my hairgrass is sending out runners like crazy, and everything else is just generally greenier.

I'll go run a test and get back to you all.

 

[fishfreek]

WHOO. Aquarium science

 

[cj10488]

as for safety: its really freaking cold, don't hold it in your bare hands for too long. otherwise its not dangerous besides its temperature, I put it in warm soda to cool it down quick

I would use some sort of gloves.. When making Dry Ice Bombs in the past I have burnt my fingers pretty bad on the Dry Ice just touching it for a few secs.. No I will not tell you how I made them I just did.. .. Anyways FW plants mainly live off of CO2 so I can see just how good it would/should work..

James

 

[Mr Burns]

actually, i'm going to go downstairs to the lab (in my office now...yes at 6pm on a friday)

believe it or not...i'm jealous

this will be perfect for jump starting my plants when i get my new tank set up. i'll try to keep the fish out for a while..through the cycle period obviously, but i'll try and dose with dry ice and maybe some seachem flourish....

 

[mrmarine]

Dry ice bombs are amazingly fun especially right when the bottle gets all fat and bloated before the BOOOOMM!....Well that sounds pretty cool nice discovery

Mr. Marine

 

[Dr.Danio]

ok. results are in.


10 gallon tank, temp 80, pH 6.0.

Added 1.0 grams of dry ice (probably less because its from yesterday and had a good bit of condensed vapor/real ice on it.) and tested pH every 30 seconds with a constant readout digital pH meter.

T= x min
0- 5.98
.5- 5.61 *added ice
1- 5.30
1.5- 5.19
2.0- 5.14
2.5- 5.10
3.0- 5.08
3.5- 5.06 * end of bubbling
4.0- 5.04
4.5- 5.04
5.0- 5.03
7.5- 5.10
10.0- 5.15

and then i wanted to get the results back to you. If the pH is any indication of how long the CO² is staying in solution, it should be back to normal in a mere 2 hours. so mayhaps thats all the longer the CO² is available to the plants. also, thats a pretty severe pH drop, and I used quite a lot of it for a small tank that I just did it to yesterday, so i hope the stress isn't too much... i just wanted some reportable data for you all.

looking at it now, I have some opinions: it seems to work, but it has some severe drawbacks. the pH drop (for using ALOT) is pretty huge as these things go, so it may not be all that healthy. and my neons were gasping at the surface after 10 minutes, so i hope they'll be ok. like i said, this is a cheap way to give a massive pulse of CO² to your tank, and perhaps why people pay more money.

I'll probably still do it as long as I monitor the chemistry and only do it occasionaly and in smaller amounts. my bigger fish at home (african cichlids in a 55 and 3 firemouths and a redtail in a 35) seemed to do just fine, and the guppies i keep around as ditherers/snacks didn't seem fazed. but still it not perfectly safe in large doses as the data shows.

so, with the data, what does everyone think?

 

[Fruitbat]

Dr. Danio....

Keep in mind that the pH scale is logarithmic so a drop of 1 point on the scale means that the water is ten times more acidic. Your data shows a drop of nearly a full point...NOT something I'd go out of my way to do to a fish.

Secondly...you've already alluded to the low temperature of 'dry ice'. At atmospheric pressure, 'dry ice' has a temperature of -109 degrees F. Did you, by any chance, monitor the temperature of the aquarium water during your test? Rapid chilling, like that I suspect adding 'dry ice' to an aquarium would cause, can be devastating to fish...stressing them to the point where they are more susceptible to any parasites or pathogens that might be hanging around in the aquarium water or substrate.

Interesting concept but I do wonder if the risks outweigh the potential benefits.

 

[Mr Burns]

possible pH and temp shock? doesn't sound like a good combo....

 

[Dr.Danio]

temp did not change at all. and yes, i do know the nature of the pH scale...

and the pH is back to normal, the fish look fine, and everything else looks peachy. now to wait till tomorow and see how the plants look.

 

[Fruitbat]

Interesting...

Understanding, of course, that water is very resistant to temperature changes because of its high specific heat, I'd still be very cautious about introducing dry ice to a populated aquarium. Of course....you were adding only 1g of dry ice to well over 32000g (assuming about 8 gallons of water and rounding off considerably) so the temperature drop certainly wouldn't have been dramatic.

As for the effects of the pH change...I haven't seen any empirical studies of the effects of rapid but temporary pH changes on fish. Interesting that the pH returned to normal so quickly....do you have any measurements of your GH and KH from before the test? It surprises me that your already acidic water had enough buffering capacity to recover so fast.

All-in-all....a very interesting experiment. I'd love to see more data as you accumulate it. Oh...as an aside....do you have any sort of control designed for this study??

 

[Guest]

This IMHO really should be classified as a "Stupid Aquarium Trick".

 

[Fruitbat]

Nahhhh Rex....it actually is an intruiging experiment. Certainly not a way to dose CO2 over any length of time but definitely a unique approach to the CO2 problem. You have to admit that there is a certain elegance to the concept.

 

[jsoong]

Ver-r-r-y interesting test. "Stupid", perhaps. But progress is often made that way.

I have one more thing to add. In additional to the massive pH change, there is also a massive CO2 increase. Rough estimate - the CO2 would have increased at least 10 times. This rapid rise can't be that good to fish. The fish were gasping prob from a massive increase in respiratory drive due to the CO2 & H+.

Incidentally, CO2 is a general anesthetic at levels of 80 mmHg (or roughly 9%). At least it is in humans! So you might be doing more to your fish than you think.

 

[Mr Burns]

regardless of what the ice is doing to the fish, this might turn out to be a great way to kick-start a new planted aquarium. i would imagine you could plant everything (under the proper lighting) then do a morning dose of dry ice every couple of days... after you've grown out, you stablize the tank then add fish. this might also be worth testing.

 

[Raimeiken]

Exactly what i was thinking! Because i'm going to start a 50 gal tank in a few weeks Few questions:

Where can i get dry ice?
Is dry ice just pure Co2, or does this stuff have other chemicals in it?
How much should i put in a 50 gal tank?

 

[betowess]

I'm glad I don't swim in that tank. Seems a little cruel to the fins. I'd get a hagen and give it a little time.