Dolly eats dry food as her main meal, and does well on it.
It's one of the pricey ones though, from the vet, as she is being treated for allergies.
But she was always on a high premium dry food...and she always drank her fair share of water.
I free feed her the dry, it's down all the time, but in the afternoon, I give her a canned food as a treat. Again, this is from the vet, an allergy one...but I have used the Whiskas foil packs before for her and she loved them.
But being a treat, it's not the whole pack or the whole can...it's only 1/4 of the canned she is eating now..or when I used the Whiskas..it was 1/2 the foil pack.
Anymore, and then she would get the loose stools.
Your cat may be having soft stools because of the quality of the food you are feeding...it's hard to say..some do well on the cheaper brands, and some...it just goes through their system and ends up in soft stools.
The companies that make the premium foods say that the cat will not produce so much stool as the food is digested very well by the cat and not all coming out the other end.
Makes sence to me...

..and I have found this to be so with Dolly.
She will be 16 years old in the Spring by the way, and has always been healthy..except for this stupid allergy thingy (I think it was really from all the cheese we were slipping her while we had our pre supper drinks and not really the cat food, but we did the change anyways)
Purrs,
Joan