Deck Jet install

[Rockcrawler]

My pool is already built, but I am wanting to add some deck jets, of course I will have to add these outside of the deck, I was wondering if anyone has done this themselves and could share some information,i.e. tapping into the return lines of the pump, plumping and valves. I already have som 1/2" pvc pipe from previous sprinkler system that I could use to plump into my pump,(that is under the deck) but the data sheets for the deck jets say to use 3/4" what would be the results if i used the 1/2" pvc pipe?

Thanks Rob