Descaling inside a hot water cylinder?

[DIYedboy]

Having just removed the outlet on top of my cylinder, I can see a massive limescale build up inside (cylinder is 9 years old) is there any way to descale the sucker? or am I being unrealistic?

 

[kevplumb]

fernox DS 3

 

[DIYedboy]

Top man Kev..........................do you ever sleep?

 

[kevplumb]

not for more than 3 hours at a time

somebody has to get the other half up for work

 

[DIYedboy]

You need a nagging wife.......................that'll get up up to 8hrs!