Driftwood = never rot?

[Lucky]

I have six small pieces of mopani wood from Petco (between two tanks), and I love them. They will probably turn the water brown for at least two weeks, with regular water changes, but personally, I like the effect.
Sometimes they'll throw in a random piece of wood that isn't mopani, though - I found a piece that wasn't mopani, and I haven't had any troubles with it, but it did flake off a few small, loose pieces of wood during the first couple of weeks. Just be careful that it's not some stick off the street.
If you want caves/tunnels, just keep an eye out for bent pieces! A lot of times you'll find some that already have unique shapes, twists, and holes that make tunnels and hidey-holes naturally. I don't think you should have any trouble if you want to take a drill to the wood (never done it myself), but there are a lot of cool shapes out there which require less effort.
The piece on the far right of this picture is an example of what you can find The middle piece has a branch that makes an arc, too (more recent picture in my signature's "10 gallon" link). My fish love swimming through it.

 

[TropicalNorth]

"Softwood however will rot more quickly,"

simply NOT true.

there are many species of 'softwood' trees.. some of these are extremely resistant to weathering and rotting.

it is the cell structure of the wood that determines if it is hardwood or softwood. often many of the 'softwoods' are harder than 'hardwood'.
an example of softwood that are resistant to rotting include cedar, cypress
and redwood. all, are resistant to rotting and some that fare extremely well in aqauria.

all wood will eventually rot tho since it is organic matter.
it's just some species will rot more slowly.

Very true. My Dad is a wooden boat builder and I know all the cell structure stuff and that some hardwoods are actually softer than some softwoods. I was just saying a general comment with the literal meaning of soft-wood and hard-wood. Maybe density is a better word. I just didn't want to get technical.

 

[DrNo]

Agree with all above... if its indeed Mopani, its ultra safe for use in the tank as long as you make sure its clean (ie. boil or hot water soak) before adding.

 

[bluejoopy]

I've had pieces of both driftwood and mopani in my tank for over two years and haven't had any problems with either. Both are still going strong. I soaked them all for a few weeks with frequent water changes prior to placement in the tank. The tank water was a little dark at first, but the fish didn't mind and seemed pretty happy with it actually. My moss and fern plants have rooted themselves to the wood all on their own and it looks pretty natural. I've never drilled it, but I do stack it so there are gaps for the fish to hide in and swim through.
Now watch, tomorrow, it will all start to crumble;-p