So the heater in my new 2.5 gallon is suspect of harming Ratchet (as are the new plants). It's a 25 watt Topfin adjustable as well as fully submersible. I believe it's leaching something into the water since the temperature has remained at a very nice constant 80.
I'm going to be going back to Petsmart/Walmart in the morning, so I want to know if these heaters are any good:
BiOrb/BiUbe tropical heater
(I don't know if Petsmart will have any suitable to a 2.5 gallon)
(also don't know if there will be a correct size for me)
If not, I think I may try a Tetra submersible heater
from Walmart, as the one I have right now in my 10 gallon has given me absolutely no troubles.