One of my Otocinclus cocama died. It was rather unexpected since both of them were eating so well. They were surprisingly not picky at all about what they would eat.
I kinda wonder if that might have contributed to it, since Corydoras and Otocinclus have rather different dietary requirements (I think). Perhaps my Otocinclus weren't getting enough algae based foods? As I tend to give my Corydoras a brine shrimp based pellet which my Otocinclus also gobble up. I'll probably have to throw in algae tablets more often or even better make my own algae based food.
I really, really like Otocinclus cocama, but I'm not sure if I want to try keeping any more of them only to have them die a month later. The first one I kept also died after a couple of months with me.
I've also modded the chiller with an external probe. It does help to cool the water down more, but it also takes very long time to chill the water. It took about 1 hour to reach 1 degree above target temp, but it takes more than 40 minutes for it to cool the water back down. I'll probably undo the mod because my bills are going to skyrocket and then consider getting a brand new, larger chiller in the meantime.