Did you check the inside of your filter for your lost Barb? Did you place 
anything new within the aquarium covering the fish? I once planted an 
artificial plant and for a week couldn't figure where my plecostamus had 
disappeared to. Found it under the plant's cup which I buried under the 
gravel. The fish had turned white, but survived! Colours returned shortly 
there after. Let me know if you find it.
Richard G
--- Maximus/2 3.01
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