advise on CO2 Tank

[jdlim]

I need advise on how to use my CO2 tank. I have this blue silver CO2 tank (written for aquatic plants). The regulator with 2 gauges is connected. When I turn the red knob or wheel anti-clockwise, the pressure goes upto 25 psi, but problem is there is a hissing sound from the wheel (I feel some air coming from there). Think if i lift it up, the hissing sound goes off. My question is whether this is normal i.e. a feature of the tank, or my tank needs to be repaired.

Any body could enlighten me on this?

[blurrblurr]

If from the knob your tank is faulty. If yours can do one for one exchange shall not be an issue, just finish it and change a tank. No hissing allow.

[diazman]

Try the bubble test. Could be leaking tank. If not knob is faulty.

[Shadow]

Do leak test as Diazman recommended, try to tighten the connection where the leak from, you might also need to change the washer depending on the situation

[jdlim]

Thanks all for the advise. I've left the tank to run as blurrblurr suggested...Brought then to my LFS, lady told me probably seal aged which is a common problem. They will top up and change seal if that's the problem. Else they will call me back.