Last night it was finally cold enough for our heater to kick on- below 68°. First thing this morning I checked on my unheated fish tank- it was 69°. My otocinclus catfish still alive, but very lethargic- just sits in one place on the driftwood, not busy feeding. Too cold for this little fish. I moved him this morning into my empty tenner. Where I had recently adjusted the temp down to 74°- in case I needed to move the peppered cories in to get them away from Perry. Right now Perry and the cories all look fine.
I've found a few ways to manage feeding them both. Perry has very sharp eyes and is much quicker to dart after a mosquito wiggler than my betta ever was. If I sprinkle a bit of gold pearls on the surface, he is kept busy picking at the little specks of food (and likes them very much!) at the same time I can sprinkle some down into the lower area of the tank. The food bits fall down where the cories can reach them, and by the time Perry is done looking for all the food at the surface, most of the pearls at the bottom have settled between substrate grains. Perry can't find them easily there, but the cories can locate with their barbels.
My other method is to wait until well after dark. It doesn't matter if Perry appears to be sleeping- resting very still under a bit of driftwood or between the filter box and the wall. As soon as my footsteps come near or my form a shadow upright outside the tank, he is right there at the glass expectantly. I can't sneak up on him. But I can sprinkle some finely crumbled flake at surface where he can just see it- I even take pains to pick out the pale yellow colored flakes from the container. Then softly drop a few sinking wafers in for the catfishes, on the other side of the tank while Perry is busy up top. The wafers are dark brown color, so Perry can't see them well in the dark, I think. In the morning his tummy is awfully fat, so I guess he did get some of it after all. But after a week, the cories still look okay I hope they're getting their fair share.
Regular servings of flake, betta bits, algae wafer or crushed shrimp pellet I can't keep from Perry. He spots the food right away- and goes meticulously across the substrate looking for every last bite of it. It looks like strong competition for the cories. So I am keeping a good amount of leaf litter in this tank, to make sure they have plenty of biofilm also. I ordered more from Tannin Aquatics- my first lots of leaves is disintegrating- especially the catappa leaves, those fall apart quickest. There are still some guava leaf and loquat intact.