First you go to Cianwood City go in theyre shop buy it from the man go back to Olivne City and go back up to Jasmine and give her the medicine and she will thank you and leave.
Pokemon Ace Trainers
Ace Trainers Alica and Alyanna
building near Pokemon center on cinnabar island
After returning to the sick Pokemon in the light tower (bring your medicine from Cianwood with you).
sorry you have to trade it to Pokemon soul silver
Zorua is a 5th generation Pokemon it is not available in soul silver.
Cianwood Pharmacy.
Transfer it from emerald OR trade it from soul silver or heart gold
to get the secret potion(medicine)you need to go to cianwood
building near Pokemon center on cinnabar island
you go to the pharmacy in olivine
Secret Potion
To get the medicine for the Olivine Lighthouse's Ampharos you must have a Pokemon that knows surf. Surf to Cianwood, get the medicine from the medicine shop, surf back to Olivine, and give the medicine to Ampharos.
you go to the city before the safarie zone.
surf to cianwood beat the gym leader chuck the fighting type weakneses flying and phychic and thunder and go to a house that's the medicine house go in talk and you will get the medicine fly with chuck's gym badge and a Pokemon that knows fly go back to the lighthouse talk to jasimane (gym leader) heal the amphoros and go battle jasimine (steel type) GOOD LUCK
After returning to the sick Pokemon in the light tower (bring your medicine from Cianwood with you).
sorry you have to trade it to Pokemon soul silver
If I am not mistaken, Ampharos cannot be found in the wild. However it evolves from Flaafy at around level 28 i think. Hope this helps :)
Soul silver is AWESOMENESS!! yes GET IT