If you can't get hydrotron. Get some cheap lava rocks for a gas grill and bust them up a little with a hammer. Then rinse them off good. Sphagnum moss would be better than peatmoss. Slowes carries it, it's cousin to spanish moss but takes alot longer to breakdown. And won't wash down in your rez. It holds water about like rockwool. Or just go with perilite your better off.