Getting rid of Stagnant water taste/smell...

[Bayerd]

Hi Guys,

My dad used to brew about 20 odd years ago. I started brewing earlier this year. He's given me a couple of the old Boots pressure barrels which I intend to use for conditioning. One of them has what I can only describe as a stagnant water smell to it. In August I put a brew in which was intended for a mate. Prior to this it had been soaked in a stronger than normal bleach solution. I racked the beer this week into demijohns ready for service. The beer definately has a taint of stagnant water about it.

Does anyone have any ideas on what I can use to get rid of it?