What Co2 ?

[michaelwgroves]

Hi,

I've been neglecting my tank for the last 12 months but am now finding time to to get it back on track.
2 years ago I introduced CO2, within a week my plants were going crazy and I was pruning weekly thereafter.
Having a 900L tank I needed a big setup, so I use 6.35KG pub CO2 cylinders. I have an SMS125 for monitoring Ph and dose automatically through a reactor.
Usually these lasted about 3 months. However about a year ago I replaced the CO2 but the plants have not grown well since and the cylinder lasted 12 months.
I think I may have accidentally got a CO2/NO2 mix, but I'm not sure. Can anyone advise what I should be purchasing as I can't rembember now. Bearing in mind my source is the local pub?

Please see my previous post below to see my setup, bottom of first page #19.

http/www.fishforum...pic=211206&st=0

Thanks
Michael

 

[peter1979]

Why dont you get a co2 fire extinguisher set up? these an be easily modified to fit a standard regulator, and are cheaper to buy than standard co2 cylinders.

 

[michaelwgroves]

Why dont you get a co2 fire extinguisher set up? these an be easily modified to fit a standard regulator, and are cheaper to buy than standard co2 cylinders.

I can get pub gas at a good price and the cylinders are a bit bigger. I think I have worked out what I did. I think the last cylinder I got was a Co2/Nitrogen mix, usually used for Bitter. Lager & Soft drinks is pure CO2 which it what I used previously.
There are two reasons why I think this; firstly, poor plant growth, secondly mixed gas is pressurised to about 180 barg, where as CO2 is only 50barg. This would explain why it lasted much longer. I also remember noticing the pressure was higher when I installed.
I guess I need to be more careful in future. I've just put a new one on which I believe is pure CO2 and it is pressurised to 50 barg. Lets hope my plants start to grow again.