Or you could buy healthy Otos. They tend to die immediately after import because they've been starved, essentially. The best bet is to ask your LFS how long they've been in their tanks. Wait til they've had them a few weeks before making a purchase. Or just order from one of the forum sellers with healthy fish that have been in quarantine for several weeks.
Just remember that they're social fish that are healthiest and happiest in groups of six or more. While algae is their preferred food, you can certainly supplement with wafers, spinach, zucchini, Repashy, et al.