Did they specify what stage of CKD? I know little about feeding homemade diets for kidney care, only that its recommended they are low in phosphorous. For now, I would be transitioning to the recommended RX diet until you figure it out, to at least start being proactive and potentially get on top of the issue for now. Once you know more, you can transition off. This way you don't have to rush and can do a thorough job of researching a suitable diet.