# CO2 Running Out?



## Courtneybst (10 Apr 2021)

Hi guys, would this be the right time to change the CO2 bottle? Or can it go lower?

Also I'm wondering if I have a leak of some kind. This 2kg bottle was only temporary until I got my 5kg bottle but it's only lasted 23 days on a 350L 3-4 bps. Is that about right? I thought it'd last at least 6 weeks.


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## jolt100 (10 Apr 2021)

Hi,  I leave mine until the bubble count starts to reduce but always have a spare cylinder. You probably have another week before it runs out. 
Have you tested for leaks with soapy water?  3-4 bps isn't excessive and should last much longer than 3 weeks. 
Cheers


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## Nick potts (10 Apr 2021)

I always wait until mine hits zero.

As above though, i would check for leaks, i get longer from a sodastream bottle at 2bps


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## Zeus. (10 Apr 2021)

Courtneybst said:


> only lasted 23 days on a 350L 3-4 bps


Not that we use BPS as an indication of the amount off CO2 being used 😬, it does seem a bit quick, how big was the bubbles 🤣, I would check for leaks also 👍


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## Courtneybst (10 Apr 2021)

Thanks guys! It's a good thing I actually ordered the new bottle already (before I knew it was running out). 

I'll check for leaks when I fit the new bottle and make sure everything is tight because when I set it up I could hear a slight hissing sound but couldn't find any leaks at all. 

As for the size of the bubbles, no idea mate lol.


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## Andy Pierce (10 Apr 2021)

Around room temperature any sealed tank with any level of liquid CO2 in it will have a pressure of 860 psi.  Either you've run out of liquid CO2, or your gauge is defective, or both.   In either case, probably time to take action.


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## Sammy Islam (10 Apr 2021)

I let mine go all the way down to near 0, if the working pressure doesn't start going down you should be good.

Something doesn't sound right with the amount of time it has lasted. I have a AS900 probabaly about 150L after hardscape soil and plants. a 3kg bottle lasts about 3 months on uncountable bubbles per sec, can barely even count the bubbles in a slowmo video.


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## Courtneybst (11 Apr 2021)

When I listen closely I can hear a hissing/almost micro bubbling noise from the in-line diffuser. It sounds like this (the link plays from a timestamp as there's multiple sounds): 

Is that not normal? I saw some people said their in-line diffusers make noises like this and it was the sound of the gas going through the membrane. What are your thoughts? When I set it up I did get a small water leak around where the diffuser attaches the hose so now I'm thinking there could be a leak there because gas only needs tiny gaps.


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## Nick potts (11 Apr 2021)

If i put my ear to the glass next to the diffuser i can hear the same noise, as you say just the sound of the gas going through the membrane.


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## nigel bentley (14 Apr 2021)

Although 3-4 beats isn't too  excessive as already mentioned, another question is how many hours do you run co2. I used to run a 2 kg Bottle for a 450l tank. Due to size of tank BC was so fast I couldn't even count bubbles and used to last about 4 weeks. Depending on co2 period IMO yours should have lasted a bit longer.

One other possibility, maybe the bottle wasn't totally full to begin with??


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## MrClockOff (14 Apr 2021)

Courtneybst said:


> View attachment 166680
> Hi guys, would this be the right time to change the CO2 bottle? Or can it go lower?
> 
> Also I'm wondering if I have a leak of some kind. This 2kg bottle was only temporary until I got my 5kg bottle but it's only lasted 23 days on a 350L 3-4 bps. Is that about right? I thought it'd last at least 6 weeks.


My last 1.5kg bottle last 9 months on 2bps 10h a day.


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## Courtneybst (14 Apr 2021)

nigel bentley said:


> Although 3-4 beats isn't too  excessive as already mentioned, another question is how many hours do you run co2. I used to run a 2 kg Bottle for a 450l tank. Due to size of tank BC was so fast I couldn't even count bubbles and used to last about 4 weeks. Depending on co2 period IMO yours should have lasted a bit longer.
> 
> One other possibility, maybe the bottle wasn't totally full to begin with??


On this tank my CO2 is on for 7 hours a day, and yes the bottle not being full to begin with is a possibility. When I went to exchange it today the guy said that to put it simply it's not the best type of FE. He went into more detail but in essence I think I got a cheapo. Will see what happens now that it's on a 5kg.


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## Andy Pierce (14 Apr 2021)

CO2 is sold by weight right?  If you weigh your bottle before and after they fill it you can tell if you got shorted on the amount.


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## Courtneybst (14 Apr 2021)

Andy Pierce said:


> CO2 is sold by weight right?  If you weigh your bottle before and after they fill it you can tell if you got shorted on the amount.


Thanks Andy, I'll start keeping track


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