The mysterious case of the vanishing fish...

When we started up the artificial stream on Tuesday we initially loaded 35 fish. We have checked every day and not seen any floaters or dead fish on the bottom. We haven't seen any fish corpses on the ground around the tanks or the riffles. The pump has a micromesh filter and is buried under rocks so they couldn't have gotten pureed there. When we did a count today, though, there were only 22 fish in the tanks. There were four of us counting and we kept coming up with the same number. Odd. We will get back to you when we get to the bottom of this.