Shock Arrester - will it solve my pipe noise problem

Can you help?
Last year I had a lot of work on the house plumbing: new bathroom and a water softener added, all functioning fine. However since the work was carried out I have had an irregular pipe noise. It happens the morning after the water softener has regenerated (which happens at 2am). When the water is run for first time eg toilet flush or shower and the mains riser starts to fill the cold tank, a loud clunking / knocking noise emanates from the riser pipe and ballcock as the ballcock tries to close off the water.

After a few minutes it will stop and not happen again until the water softener regenerates. The plumber who fitted the bathroom and softener tried to resolve by refitting the ballcock (old one was pretty scaled up) to no avail. He didn't really have any other ideas after that.

My usual heating system plumber (not the one who fitted the softener)
suggest fitting a Shock Arrester as he believes the noise is caused by some kind of resonance in the plumbing system. He cannot be 100% sure but says he has seen this resolve similar problems elsewhere.

I wondered if anyone had ever come across such a problem ? and whether a shock arrester is the answer?

Thanks for any inputs - regards Iain

Water Hammer , you could try changing the ball valve for a Torbeck type ballvalve , sometime's work's , & they are not dear , think you can get them in B&Q , or try a bigger float/ ball on existing b Valve , u used to be able to buy specific disc's that could be fitted on ballvalve's in order to alleviate water hammer , cannot remember what they were called ???

Hi Transam, thanks for your reply, I will check out which type of ballcock I have got and maybe try that first if it is not already a Torbeck. What did you think of the Shock Arrestor idea. I did a search on Water Hammer and quite a few times people seemed to have considered a Shock Arrestor.
Regards Iain

They do work , used to make them our selve's , all you are basically doing is providing an air cushion ( for want of a better word ) used to put a tee on ball valve than go up with a short piece of inch pipe with a stop end on , it's always got air in it , seen some use hand grenade type exp vessel's out of combi's ( mini exp vessel's ) ,