Are iPhones water tested with just fresh water?

It depends how long it was soak, or did you dry it immediately but there are water probably in some parts inside and dried water cause corrode any expose components inside-cause corrode so many tiny pins inside, most components are integrated circuit these are very still vulnerable to short circuit and cause an issues….you will know however if your phone behave not normal means something wrong…Phone are not really water resistant as the (30 mins )….manufacturer claims, though can can cope with a bit splash, moist, never submerge to water (fresh, salt is worse as it penetrate the board or any components inside, the problem of phone being soak to water is…. when is on as all components are working 100% then suddenly short circuit…. this damage most of the components inside (ICs) can pcb or board main board whatever you gonna call it can be submerge to water or can it be washed absolutely yes but with no supply voltage it can be be clean with water or 99.9 % alcohol…I am a repair tech… mainly high end amps….