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For a 95g tank, how long will a 20lb CO2 bottle usually last before I need to refill it?

I'm the kind of lazy person who doesn't want to go refill a CO2 bottle too often, and I'm wondering if it would be a good idea to buy a 50lb!
 

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My 5lb co2 tank lasts about 4-5 months at about 4-5 bubbles per second so that will give you a rough idea. I figure a 20lb tank would last around 16 months at that bubble rate. Less if you have a higher bubble per second. Again just a rough estimate. You should get at least a year between refills I would think. Maybe less thats a big aquarium.
 

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I prefer the smaller co2 tanks because if a 20lb tanks burst disk blows it could suffocate you quickly if it is in an area with poor ventilation. Not likely to happen but always a possibility. Just food for thought.
 

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There's a LOT of variables. Ignoring them all to provide a VERY rough estimate, maybe 3-4 months for a 20lb.

Before considering a 50 pounder, make sure it won't be too much for you to lift. Should you have a relatively small leak, you can lose even 50lbs. of CO2 in just a few weeks, it's less painful to lose 20lbs. Should you have a massive leak, I think I wouldn't want to be in your house!

Two 20lb. tanks could be an alternative. When one empties, you can have it refilled at your leisure, instead of rushing to go do it.
 

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I have a 20lb on my 75 gallon which runs 24/7 , drop checker stays green at around 1bps and I'm on my 2nd month.
 

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Danakin is right. Stay away from a 50lb cylinder. They're about five feet tall and weigh around 175 lbs. I'm running a 5lb for over three months now in a 50g tank. You can get one on Amazon for around $70. The "buy two" idea sounds like it would fit your needs...
 

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Thanks, kevmo! Exactamundo. That's why I tried to explain in another thread about the 20oz CO2 paintball tanks needing to be drained all the way to get an accurate fill because of the variance in vessel size. And as I said before, anyone in the New Orleans area that has questions or need with CO2, PM me. We have a full servcie paintball shop and I can fill your cylinders at a nice discount if you mention TPT...

20lb cylinder should more than fill your needs Cthulu! Good luck!
 

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I'm looking at a 20lb for myself, which would be shared between a 75 and a 10, so I think we are in the same boat.
One thing I would love to know though, is if people are estimating the time before refill assuming that co2 is going to be on 24/7
I know with myself that I am going to have mine on a timer, that way I'm not wasting any co2 and that way my fish aren't being gassed out.
 

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I was under the impression that a 50lb bottle weighted 50lb...?
As mentioned, a 50 pound cylinder holds 50 pounds of CO2 gas; the weight of the cylinder is in addition to this 50 pounds.

In the lab, we use 50 pound gas cylinders; they are impossible to lift up by yourself. If you don't have a dolly, then you'll have a very tough time moving them.

Also, forget about moving them if you have a carpeted floor.
 

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I'm looking at a 20lb for myself, which would be shared between a 75 and a 10, so I think we are in the same boat.
One thing I would love to know though, is if people are estimating the time before refill assuming that co2 is going to be on 24/7
I know with myself that I am going to have mine on a timer, that way I'm not wasting any co2 and that way my fish aren't being gassed out.
No. Relatively few people have pressurized CO2 without a solenoid, as it makes absolutely no sense to run CO2 24/7. So the estimates you'll see for any given size of cylinder will generally have one agreed-upon timeframe. The estimates lower than that timeframe are usually a mix of 24/7 CO2 and "I've had a small leak for quite awhile but haven't figured it out yet". Estimates over that timeframe are generally people who think they're injecting more CO2 than they really are.

But, again, when most of us talk about a regulator, we're actually talking about a reg, solenoid, and needle/metering valve.
 

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So, overall theme is that a 20lb should work for at least a year.
How exactly can you tell how much co2 is left in the tank? Is it one of the dials on the regulator or something?
 

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Well, looking back through the responses, I see 3-4 mo on the low end to 1 year on the high end. I imagine it will be something in the middle. "At least a year" sounds like a stretch, based both on my experience and the responses in this thread, but it'll last awhile.

Your high pressure gauge won't move from around 800 psi for the first 90 or 95% of the life of the cylinder. After that, it will begin steadily dropping. At that point, you'll have a few days to a couple weeks till you're completely out of CO2.
 
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