Make 3% epsom salt solution (1/2 cup of distilled water with 3/4 teaspoon epsom salt). Use a pipette with an airline tubing at the end and force feed a small amount of this solution until he eats. Feed the solution with a pipette for 5 days. If he starts to eat before the 5 days is up, soak food that he will eat (freeze dried or floating pellets or gel based food) with this solution until it will not hold any more. Continue feeding this epsom soaked food for the rest of the remaining 5 days.