Catbrat, it could take a few weeks to a month, don't give up. You probably feel like you are taking 2 steps forward, then 3 three back, then 1 forward, etc. Remember, it's a living animal, not a machine. Patience is the key. You may find that after a month you cat just doesn't do Wellness, then you move to a different brand.
If we though that on food was good for all pets, then we would only carry one food, but we don't. We carry many, for this reason.
Best of luck.
Axiom M80, VP180, Qs8, EP500