Arriving an hour early, I removed all but a small handful of the gravel and replaced it with white aquarium sand, dropping a few pieces of gravel around for viewing pleasure. (When it was down to almost bare bottom, I finally got to see all six kuhlis at once, for more than a few seconds!)
And now I've discovered, after tossing the gravel, that the Aqua Clear filters do not like sand. One tiny particle gets in the fan thingy and I have to go poking inside until the blades turn without that horrible scratching sound. Twice the motor then refused to even try, and I had to disassemble the entire thing.
Now that the sand seems to have settled (some of it was floating??) the filters are running fine. And a good thing, because the kuhlis reeeeealy like the sand
I also rinsed off and dropped in an Indian Almond leaf. It's floating around for now, but should eventually get waterlogged (waterleafed?) and settle to the floor.
