Posted: Wed Apr 22, 2009 5:55 pm
The 180 gallon is a perfect size for 2 RES. If you get a Penn cooter, you'll eventually need either a larger tank, or a separate tank for the cooter. I think Penn cooters get bigger than RES too.
Plus, like zoologist said, your two, established RES will see the new cooter as an intruder to their territory, and will likely bully the cooter.
If you do decide to take in the cooter, remember it's recommended you quarantine the new turtle for at least 90 days. Turtles are very good at hiding illness, an you don't want it making your existing turtles sick.
Ralpheal, "The 'L' is silent."
Frankie, "Young at heart."