I have a 6-zone Nelson system hooked up to my house's (CITY) water supply - hooked into the water system in the basement. I get the normal tick-tick-tick when the sprinklers are on, which does not bother me.

The problem is that when the sprinklers first kick on, the "KA-THUD!!!" is ridiculous. I can actually FEEL it in my bathroom floor and hear it in every part of the house. It's only when the sprinklers initially kick on.

I don't want to permanently damage pipes or come home to a wet basement. I have one water hammer arrestor installed under the kitchen sink, but that's it.

Would it help to put another arrestor where the irrigation pipe taps into the house water?
What else can I do?

Thanks in advance.