Parts Of Fish In Fish Sticks Is Driftwood Supposed To Sit At The Bottom Of The Fish Tank?

Is driftwood supposed to sit at the bottom of the fish tank? - parts of fish in fish sticks

I have a piece of driftwood is large enough that I had when I bought the tank from the previous owners. It is a flat piece of wood under the role that sticks. Let them sit in the matter, or should I put on top of the bowl and let them swim? Then I went into the new vessels do not fish (is still) and his half-floating. I say half, because you can swim and because I like the gas cap.