thanks for the advice guys!
i've moved a few of his favorite decorations over to the new tank hoping that it will introduce some of the bacteria and such and help make it feel more like home.
using the old filter seems like a great idea, but i've got a few questions.
should i move the old filter at the same time i move him or put it in there and let it run for a few hours? if so, will he and his tankmates (a pleco and an albino frog) be okay in the old tank for a few hours without a filter running? I was going to leave the pleco in the 10 gal
for a few days after I moved the other two to make sure there would be enough algae buildup for him to stay fed, but I suppose I could just go buy some algae flakes if I'm going to try this method.