Thanks @
Buddy.
Now some bad news. I will be the first to admit that I have neglected the tank a bit over recent months :rolleyes
Last night I noticed that my small helio and my branching torch were not looking happy. Tonight, brown slime had taken hold of the helio and one head of the torch - and one of my hammers was not looking happy :(
I siphoned out the helio and one head of the torch - the water absolutely stank !!. An hour later the hammer is looking a bit better and the other two hammers look OK.
But, I know how quickly this can spread - I suspect that I will be looking in the tank before giving my wife a kiss at breakfast time tomorrow ;)