Before I got my hypp nh horse I researched absolutely everything I could find on it. If you wish to feed more than hay (timothy grass hay is excellent) you can safely feed Senior Feed. Oats are another safe feed. What you are looking for is very low potassium and these are down in the 1%. He is better with turnout and movement. For salt I use mainly pickling salt and about 1/3 household salt. They do need the bit of iodine in the household salt. A lick does not provide any horse with enough salt because licking salt results in a sore tongue. You want to keep these horses drinking lots and peeing lots. If you have to trailer of 4 hours or more, talk to your vet about administering a diuretic to encourage him to pee. If you go to a show take a baggie full of salt, even mix several tbsp in his feed to encourage him to drink. Do not put him on a multi vitamin mineral supplement as it is high in potassium. So are carrots. Half a small carrot is ok. If you wish to learn about which "treat" foods are safe google hyperkalemia. The site applies to people but the list is helpful in identifying amount of potassium. Small piece of apple only. For treats I buy a 50lb bag of alfalfa cubes and break them in to wafers. Other than that it's timothy hay, oats, and senior's. Presently he is getting less than a pound twice daily, mainly so I can easily check them over. If you have other questions pm me and I'll answer them the best I can.