The people who sold them to me didn't say they ate algae. The websites that I frequent like loaches.com are the ones that say they eat algae. That and my loaches.
Thanks for the suggestions everyone! The family friend came through with some pottery that was covered in healthy green algae. Currently rotating each piece as the loaches clean it. The extra pieces are outside in the 50gal. with two feeder goldfish and a bunch of rocks. Lots of sunlight and plenty of food seems to be doing a world of good for growing algae quick. Once everything gets established, I shouldn't have to worry about running out of algae anymore.
I did check around for local collecting, but the water here is too polluted to be safe for my tank. brich999, I wish I could take you up on that offer, I really do. I kinda live too far away for that though.
As far as prepared food went, the still aren't biting, but at least I have enough algae for them. I tried some home made gelatin mixes, frozen bloodworms, blanched zucchini, squash and a couple other veggies that we had around the house. The gelatin mix was the only one that received any attention, and only when it was smeared on a rock, but even at that they barely ate any. I may yet buy some algae wafers, but I'm not sure what I'll do with the extra if they don't take to it.