[vanostav61]

Hi everyone,
I was recently looking for a CO2 system for my 20gal tank and came across this citric acid and sodium bicarbonate reactor on Amazon. So I was thinking, what if I fill it with dry ice instead of citric acid and sodium bicarbonate so that it would be less messy?. In the description it states that the bottle is rated to hold over 1000PSI so too much pressure should not be an issue.

What do you guys think about it?

 

[Darkblade48]

I mean, I guess it's possible, but you'd be surprised how fast dry ice sublimates. Do you have readily access to cheap dry ice?

 

[minorhero]

How would you introduce the co2 into the tank? Does sublimating dry ice build up a lot of psi? I have no idea if it does or not but you need around 20-30 psi to use a diffuser reliably. And unless its going to last a couple of weeks regular diy co2 would be better. I am using a bell diffuser with jello yeast co2 generator at 3 weeks it is still going strong. I think the combination of the slow release jello and bell diffuser is a pretty good combination.

 

[#DizzyIzzy1]

Um, no.https://www.youtube.com/watch?v=ICO48V6FUJs

 

[Thenoob]

Hi everyone,
I was recently looking for a CO2 system for my 20gal tank and came across this citric acid and sodium bicarbonate reactor on Amazon. So I was thinking, what if I fill it with dry ice instead of citric acid and sodium bicarbonate so that it would be less messy?. In the description it states that the bottle is rated to hold over 1000PSI so too much pressure should not be an issue.

What do you guys think about it?

Interesting idea. If the cylinder is truly rated for 1000 psi it should work in theory since pressure will only rise until it reaches the vapor pressure of CO2 (about 830 psi at room temp) at which point it will change phase to a saturated liquid. Since the dry ice is so cold, you will likely see much lower pressure since the low temperature suppresses the vapor pressure. However, things could go very very wrong if you manage to liquid lock the tank, i.e. if the tank is completely full of liquid CO2 with no vapor space at the top. If such a condition occurs, even small changes in temperature can cause massive pressure increases leading to rupture. I can't remember if solid co2 has a lower or higher density then liquid co2 so I can't comment on the likelihood of this occurring. Now this is all theory, if it were me I would not attempt this unless I was very confident in the cylinder (DOT certified, hydro tested, etc). Even then I would be leary since a rating of 1000 psi leaves little margin for random variability which I would be concerned about since we don't know what safety factor the designers included in the rating and if the tank was actually proof tested at 1000 psi or higher (1.5 times max working pressure is common for hydro/proof testing). So to reiterate I personally would not do this.

Safety and theory aside, I would think a normal pressurized system would be cheaper in the long run unless you have ready access to cheap dry ice.

 

[jctalbert]

I have been using dry ice in paintball tanks using an AquaTek mini regulator for several years now. For me... it is the cheapest and easiest method of adding CO2 to my 2 planted tanks. I am always surprised by the comments of others who... I think... are basing their "knowledge" on alarmist/purist ideas written on forums, etc... If you haven't actually done it... it is easier to just parrot the armchair chemists and people who are running big systems on many tanks at the same time. Big tanks make sense on big set ups... but what about us little guys who want CO2 also?

I invested in the small tanks and regulators JUST before my local sports store stopped refilling CO2. No larger AirGas place will touch anything under 5 lbs... and usually won't for less than 20 lbs tank in my area. So.... I was forced to figure out how to use and keep my investment.

Spin the tank valve off... crush up 2.5 lbs of dry ice (mortar and pestle style in a metal bowl... use a funnel and stick to get the ice chips into the open tank... put tank valve back on and let it cool down over night. I do replace the rubber washer gaskets fairly often since CO2 seems to harden them over time. I start with 2.5 lbs so that I am fairly close to 2lbs of actual ice in the tank by the time I close things up. I have NEVER had any trouble and get about 4 weeks of CO2 for about $4.00 worth of dry ice and 15 minutes of work. Seems (and is!) a great solution. I have gone the CO2 cartridge route. Expensive! I have a citric acid/baking soda reactor. It works but no matter how fast I try and get the tank sealed up after mixing things I have never gotten more then 3 weeks of use out of it. Plus... long term the needed materials are much more expensive than dry ice. I have also DIYed my own out of pop bottles and yeast. What a head-ache... and short lived. For me... small 2lb paintball tanks... an Aqua-tek mini type regulator and dry ice. Perfect for my 55 gallon and my 40 gallon planted tanks.

 

[Profector]

I have been using dry ice in paintball tanks using an AquaTek mini regulator for several years now. For me... it is the cheapest and easiest method of adding CO2 to my 2 planted tanks. I am always surprised by the comments of others who... I think... are basing their "knowledge" on alarmist/purist ideas written on forums, etc... If you haven't actually done it... it is easier to just parrot the armchair chemists and people who are running big systems on many tanks at the same time. Big tanks make sense on big set ups... but what about us little guys who want CO2 also?

I invested in the small tanks and regulators JUST before my local sports store stopped refilling CO2. No larger AirGas place will touch anything under 5 lbs... and usually won't for less than 20 lbs tank in my area. So.... I was forced to figure out how to use and keep my investment.

Spin the tank valve off... crush up 2.5 lbs of dry ice (mortar and pestle style in a metal bowl... use a funnel and stick to get the ice chips into the open tank... put tank valve back on and let it cool down over night. I do replace the rubber washer gaskets fairly often since CO2 seems to harden them over time. I start with 2.5 lbs so that I am fairly close to 2lbs of actual ice in the tank by the time I close things up. I have NEVER had any trouble and get about 4 weeks of CO2 for about $4.00 worth of dry ice and 15 minutes of work. Seems (and is!) a great solution. I have gone the CO2 cartridge route. Expensive! I have a citric acid/baking soda reactor. It works but no matter how fast I try and get the tank sealed up after mixing things I have never gotten more then 3 weeks of use out of it. Plus... long term the needed materials are much more expensive than dry ice. I have also DIYed my own out of pop bottles and yeast. What a head-ache... and short lived. For me... small 2lb paintball tanks... an Aqua-tek mini type regulator and dry ice. Perfect for my 55 gallon and my 40 gallon planted tanks.

Good post. I know I've been guilty of repeating what I've heard/seen without trying it myself. I usually add the disclaimer "from what I've read." I agree the yeast method isn't ideal. I've tried it in the past. It worked but I didn't enjoy the extra effort. I looked into the citric acid/baking soda reactors and read the reviews. People seem to like it. Some folks found it easier to use ice cubes instead of water. That way they could get everything reassembled before the reaction got started. In the end, I decide to stay with co2 tanks. I can switch out tanks every few months pretty easy and a decent setup doesn't cost too much more when compared to the costs and extra work the other setups require over a couple of years.

Really though, I never would have thought about using dry ice.