I made a Thing

for my kuhlis- a little feeding station that (supposedly) only they can get into. Small food-grade plastic storage container upended, with the lip removed. It had three small gaps near the base- level with substrate floor when pushed in about an inch,

a hole on top to drop the food in, and smaller holes to allow current through.

It worked fine for a few days. The kuhlis learned quickly how to get in for the food, and naturally followed the curves of the wall (outside or in) to locate the gaps.

But the cherry barbs can smell that tempting food, and even if I already gave them their own portions they always want more. The smaller ones figured out how to shove their way through the little doorways- and then couldn't get out and panicked all over the place, darting anxious circles. I had to keep lifting the cup to let them out. It was just one at first, but last time I fed the kuhlis three got in there. Too dang crowded and defeats the purpose.

I pulled the thing out, will try to make another one with the entry gap smaller, just big enough for the loaches. (It's hard to do without cracking the cup. I use the smallest bit in a drill, and a pair of very sharp scissors to refine the edge).