# why is my CO2 still flowing?



## morefirejules08 (24 Nov 2011)

Hi
i finally got some plants in my tank today so had the first chance to get my CO2 running, its a pub cylinder and one of these regs, http://www.ebay.co.uk/itm/Co2-Worki...159?pt=LH_DefaultDomain_0&hash=item27bab88fcf i have it on a timer to shut off at 7pm, an hour later there are still CO2 bubbles flowing through the bubble counter so 5 mins ago i shut the cylinder off but there are still bubbles coming through! whats going on to make the gas still flow??

cheers


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## Alastair (24 Nov 2011)

It could just be pressure in the pipe still going through. What diffuser are you using? If your concerned that the flow is still coming out of the reg with the cylinder off, which I doubt it will mate, pull the tubing off that goes into the bubble counter and see how long it hisses for. It'll stop instantly. I'll be sure it's just co2 left in the piping that's taking it's time leaving, as when the solo pod shuts off, the pressure to the diffuser drops so isn't being pushed out at the rate it was when the reg was on. 
To test it properly, get a jug of water, keep the co2 hose off that goes onto the bubble counter, pop the end into the jug, make sure the cylinder is open and with the solenoid switched off see if it still releases co2 for any length of time, if not, great, then double check by turning on the solenoid whilst letting the gas out, then unplug and check how long it does it for then. I'll be positive it's just co2 in the pipe. Once your cylinder is turned off it wouldn't allow co2 to keep coming out and neither would the solenoid, unless you haven't out a non return valve before bubble counter, as that would let water run back to the solenoid causing it to stick open


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## John S (24 Nov 2011)

In my experience the bubbles won't just stop immediately as there is still pressure in the tubes. It takes my set up about 20 to 30 minutes for the bubbles to finally stop.


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## morefirejules08 (24 Nov 2011)

well i've just had a play and it seems the reg holds quite a lot of gas after the solenoid is shut,if i turn the bottle off and take the pipe off then put my finger over the hole after a few seconds there is a pressure build up and a hiss when i release it. i also closed the cylinder and solenoid then opened the needle valve up fully and it hissed for a good few seconds before the working pressure dropped and everything stopped.


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## Alastair (24 Nov 2011)

That's normal mate.


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## morefirejules08 (24 Nov 2011)

so do i just need to work out how long it'll carry on flowing for an adjust my timer to suit?


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## spyder (24 Nov 2011)

It's at the end of the photoperiod so not really important if at a slow rate. If you wish to save gas then you can try it off half hour earlier.


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## morefirejules08 (24 Nov 2011)

ok some more investigation and my solenoid was letting gas through wen closed! i just had it apart and there was a couple of shards of brass floating around, it looked like swarf from the machining process so i removed it, checked the seal and put it back together. no more bubbles though the counter now


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