Yes that is the Rebin Beack alright, if you look on Goggle Eart and zoom you can see how big the pool is --ok --yes -- cos it is n300M from the Beach, but, at the price, the dolmus costs still make it good value.
I have heard great reports from Oykun but also they jumped the prices a lot over the years, also Harman is supposed to be very nice but a long way from beach.
Its always difficult, if you look up Delta Hotel, (way beyond your budget I know) it will give you an idea where the sort of centre of the Beach area is and where the water dolmus to Fethiye goes from -- worth taking that trip!
Only thing with Rebin Beach it is a long way from the Water park!
Meldrew