Veronica: I like to use a mixture of dry and canned (for the cost). That way I can spend a little less, and still get high quality diet. I just add water to the mixture, and they drink it up. They'd never drink that much water by itself. Throw in some canned food and they are THRILLED.
With Urinary Crystals, the more water the better. That is a HUGE benefit. The more water flowing through the system, the less likely crystals will form and make chunks.
One piece of advice -- if your kitty had crystals before in his urine, always get routine checks on the PH of the urine -- have your vet test his urine in about 1-2 months after the new diet. If the PH is too high or low, crystals can form, and can block his urethra. Then you and he are in big trouble.
BTW: Your kitty looks EXACTLY like mine! Especially in the body markings.