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purge43
12/09/2016, 10:15 PM
My dealer let me "trade up" to a 20lb bottle of CO2 without any additional deposit, which saves me a large amount per unit of CO2. Since using it I wish I would had done it a long time ago, but I have a safety concern. My training in these things is not up to date ( gas migration, O2 displacement etc). I keep the tank in the same house space as the reef ( approx. 28' x 15' , 10' ceiling) I sometimes fall asleep on the couch and some of our 4 legged friends spend a lot of time there. We use blown hot air furnace for house heat. I'm worried if there is a situation where something fails and the entire 20lb tank leaks out what affect would that have on the breathing air and its ability to sustain life?

salty joe
12/10/2016, 12:50 PM
A quick search found this. I never heard of anyone dying from a 20 lb bottle of CO2, doesn't mean it hasn't happened. CO2 detectors are available.

https://www.analoxsensortechnology.com/blog/2016/02/11/carbon-dioxide-gas-detection-dangers-co2/

http://www.hse.gov.uk/carboncapture/carbondioxide.htm

Vinny Kreyling
12/10/2016, 06:09 PM
I recommend strapping the tank to something solid so it can NOT fall over. IF the valve breaks it could take off like a rocket causing major damage.

purge43
12/11/2016, 01:20 PM
I recommend strapping the tank to something solid so it can NOT fall over. IF the valve breaks it could take off like a rocket causing major damage.

yes! I saw a propeller take off the top of a ramp fire extinguisher, it went thru a double cinder block wall like butter

Zatoichi
12/22/2016, 12:36 AM
Egads I never even considered this LOL I have had 20 pound tanks exclusively in the past too much trouble holding down the 5 or 10 gallon bottles constantly

Sent from my SM-J700T1 using Tapatalk

125mph
01/05/2017, 12:03 PM
My 10lb bottle lasts a year lol..

Optionman
01/20/2017, 12:34 PM
my 5lb bottle lasted 6 months!

slief
02/01/2017, 10:07 PM
I'm on 2 years with my 20 pound bottle and the bottle still reads 700 psi! This has lasted me much longer than 20 pound bottles did back in the yesteryears... Back when I started using calcium reactors more than 20 years ago, I think I was lucky to get 6 months out of one of my 20 pound bottles. That was when I had crappy regulators and lousy feed pumps. It seemed back then we set the co2 rate to 1 bubble a second and the entire calcium reactor dialing in was very imprecise.

thepotoo
02/02/2017, 07:49 AM
I'm in a similar situation, so was interested in running the numbers.

20 lbs CO2 is 174.856 ft^3

28 ft * 15 ft * 20 ft = 4200 ft^3 fresh air

~4% CO2, which is ~40000 ppm, too high (https://www.kane.co.uk/knowledge-centre/what-are-safe-levels-of-co-and-co2-in-rooms).

CO2 is heavier than air, so most of it will sink to the bottom 6 inches of the room, unless you have good air flow. Also, it's not going to stay just in that one room. Figure out how big your whole house is, and re-run the numbers based on that. If your house is 8x bigger than that room, it'll be fine for ~8 hours, probably long enough for the CO2 to start to dissipate.

tkeracer619
02/02/2017, 11:28 AM
Seriously doubt there would be any issues if a bottle let go. Strap the bottle.

Slief, just remember that a co2 bottle will continue to have high pressure and then fall off rapidly once the liquid co2 has converted to gas. Check out the chart, if you have 700psi @70deg f you are probably around 15%. If you have a two stage reg no worries, you will probably get a few more months. If you have a single stage go ahead and have it refilled as the regulator won't be able to stay consistent as bottle pressure changes. This is where the end of life dump occurs in single stage regs.

Personally, co2 is cheap, I swap the bottle when I see the pressure drop. I'm good for another year or so :)

http://co2doctor.com/images/co2pvstemp.gif

slief
02/03/2017, 09:16 AM
Seriously doubt there would be any issues if a bottle let go. Strap the bottle.

Slief, just remember that a co2 bottle will continue to have high pressure and then fall off rapidly once the liquid co2 has converted to gas. Check out the chart, if you have 700psi @70deg f you are probably around 15%. If you have a two stage reg no worries, you will probably get a few more months. If you have a single stage go ahead and have it refilled as the regulator won't be able to stay consistent as bottle pressure changes. This is where the end of life dump occurs in single stage regs.

Personally, co2 is cheap, I swap the bottle when I see the pressure drop. I'm good for another year or so :)

http://co2doctor.com/images/co2pvstemp.gif


Good chart with some great info! Thanks for posting it. The 700 PSI is with the bottle at around 60*. Maybe a bit less but I do plan on changing the bottle possibly as early as this weekend if I have time. if not, next week sometime. That said, I don't run a 2 stage. i run the Carbon doser but I also have the output pressure set to 3 PSI and thus far, it's been very consistent with the lower pressure. Either way, I know it's time for a refill.

tkeracer619
02/03/2017, 06:03 PM
:thumbsup: You're welcome! At 60deg you are probably just at the point where it stops dropping, that is unless of course your gauge is off and the thing has read 700 since new.

d-man
02/25/2017, 08:10 PM
What should the outlet pressure be set between?

tkeracer619
02/27/2017, 03:53 PM
What should the outlet pressure be set between?

There is no set standard and it depends on the regulator/needle valve/solenoid/electronics that the regulator uses.

That said I vary between 3 and 15psi depending on how much gas I need.