I am SO distraught! Yesterday, we did our tank cleanings. The yoyo tank got a 50% change (typical once a week change). I took out a large decor piece and put some new artificial plants in there and one new piece of real driftwood because I know the loaches love their driftwood. Usually, one of the three loaches will be MIA for a short time after a cleaning. I think he gets more stressed than the other fish about it. But this was yesterday at about 4 PM. Last night, I still couldn't find him, and this morning I couldn't find him. I also have cichlid stones in there and, although I haven't seen them stay in the stones, I've seen them investigate them, so I double-checked those. No loach. Checked the little hidey holes in the driftwood. No loach. This tank was set up prior to my love affair with loaches, so the substrate is a medium sized rounded gravel. I have seen them dig caves underneath stones through the gravel, no problem. Is it possible this guy is hanging out beneath the gravel? Could he survive staying there for 24 hours? After work, I'm going to do a 25% water change, remove all the decor and carefully move the gravel to see if he's there. If he's just disappeared into thin air, I'm not only going to be very spooked but extremely heartbroken. I love my loaches. :'( Anyone have any ideas, thoughts, experience with loaches MIA? Thanks, guys. Edited to add: I know he didn't go up the python. a) he wouldn't fit, b) I don't take my eye off that python for a minute when using it.