I have the API test kit that i can get a reading of my tanks. One thing I've learned is that a 50% water change a week, or even a month can seriously shock your fish at the sudden water chemistry change, which is why i try to do 10-20% weekly, if not a couple times a week.
My cories are only supposed to get from 1-1.5" long.
I read up on SAEs and saw they get up to 6"... way to long for my tank... I originally got them to help clean the algae off my tank... nope, no luck with that! LOL Maybe, to keep them safe i can see if i can return them to my lFS.
I've been keeping an eye on my female Bettas... I can't see one without the other. The reason i bought those two, was because in the tank they were always close to each other, where one swam the other followed, and they kept within each other's eyesight. When we put them in the bag together for bringing home, there was a LOT of gill flaring, and i saw them actually "fight" pushing each other hard... so we separated the two into two different bags. When I put them in the tank, they kept apart from each other, but now i"m watching them, and they're swimming within two inches of each other in my big(ish) 10 Gallon long... the only time i see nudging (Which is done as what seemed gentle) is when one bumps into the other... maybe i have weird fish?
My male Betta, Erne will eat from my fingers. in fact, when i put my hand in the water for any reason, to move plants, move stuff, etc. he'll come up and sometimes nudge my hand with his head, and want to be "Pet" whenever my hand is in the tank he's watching me, and if i pay attention to other fish he swims into my view.... It's quite cute really.