cat diet

My boyfriend and I are planning to move in together, taking our cats with us. The problem is, that his two male cats are used to a diet of tinned food on a morning, and dried food at night, they also drink plenty of water. I also have two cats (females), who eat tinned food for every meal, and have dried food as a treat (they go really mad for it!) Although I make sure that water is available, they don't ever seem to drink it. How can we feed all four cats when we move in together? One of my boyfriend's cats seems to eat a lot more of the dried food, and not so much tinned food, but if we were to leave bowls of dried food out I'm afraid that my two would eat it all as quick as they could, because this is what they do now! I'm also worried that dried food can cause kidney problems later in life - is this true?
Thank you

I've never heard anything about dried cat food causing kidney problems!

Dried food is good for cats. Wet food contains more water, so make sure your cats drink plenty of water if you switch them. Just make sure you feed them a higher-end brand (not generic).

cats that dont drink enough water are at higher risks of getting urinary tract infections. dry food does not "cause" urinary problems but not drinking enough water will. so its a good idea to feed cats tinned food that dont drink much to ensure they are getting enough water.one meal dry and one meal tinned should be fine.my suggestion would be to start now feeding your cats the same way as him. they most likely go so nuts over the dry food because they dont get it that often so if you start feeding it to them at night(like your boyfriend feeds his) and give them the tinned meal in the morning maybe by the time you move in together they will all be on the same feeding schedule and that will make it much easier. i give my cat 50%tinned and 50%dry. dry in the morning and tinned at night. they were hardly drinking any water at all. i also bought a running fountain that is filtered which has increased their water intake. good luck. hope this helps you.

I leave dry food out all day and night. I feed my cat wet food in the morning and in the evening. I don't know what is the right amount of water that a cat should be drinking, but she does drink a little. I hope it is enough. I understand cats drink very little.
But she pees at least once a day, and poops once a day, so I guess all is well with that.