Sturvite Crystals in my cat

My cat was recently diagnosed with having sturvite crystals and was blocked. He spent three and half days at vet. My vet recommended changing his food to royal canin so urinary for cats. I feed him the canned as well as alittle dry. Has anyone else used this food and what was the outcome? It breaks my heart to see my cat sick and I want him to be healthy. Any advice appreciated

My shelter routinely uses SO with good results.  having various water sources including possible a pet water fountain and plenty of wet SO food is good too.