Not the worst feet I have seen but bad. Remember no hoof no horse. I know you said he is more sore without the shoes, but if you can find a certified bare foot trimmer and work together with diet, environment, and trimming it will take time but he will be better off. There are great boots on the market to help him until his soles toughen up and as long as their is no damage to the inside of the hoof which can only be seen with an x-ray, then shoes are causing more damage. A good feeding plan is going to go a long way to help your horse. The water is not the biggest culprit here there are other factors at work, the horse is not growing a good hoof and that has to be fixed from the inside. Keeping a horse stalled on shavings will make it worse. The shavings dry their feet out and horses are made to walk and move about, which promotes circulation in the feet, which is needed to grow and toughen the feet. If you must keep him in a stall just put sand in it, and keep it clean. Best of luck.