Interesting. That's actually good to know. Perhaps my little sensor is broken or doesn't work properly. I've stuck it in a completely 100% new water, fish-free tank and it's been a very pale green ever since it touched water. Doesn't seem to change. Thanks for that.
Either way, both of my fish seem to be doing just fine now. I did a 40%ish water change on the tank to clean out some of the plant debris and it seems to perhaps have helped, too. I think Jabu-Jabu must've just over stressed himself from seeing his reflection or something. He's fine today and very much back to his charismatic self.