Just an FYI:
I have an unheated, planted tank (temp around 65-70) and I've had difficulty gathering information on how well plant, fish, and invert species do at these temperatures. Most tanks are tropical, after all.
It's a new planted tank and I'm a newbie. What does that spell? Algae, and lots of it. After doing some research and getting a lot of conflicting "temperature requirements" for shrimp species, I decided to try out some shrimp. I went to a few LFSs and found some red cherry shrimp (only 3.99 each--couldn't resist) and some yamato shrimp. I bought three cherries and two yamato.
Anyway, its been about two weeks now and I'm glad to say that both species are doing wonderfully in this unheated tank.