It floated bad. I had to attach a 4 lb porcelain base to the bottom.
I had a feeling that was the case .... yeah if I was you I'd start over. First spray the hell out of it with a pressure washer, go over it with a wire brush at the same time. Just to remove any loose or near loose particles. Plus considering what happened. Then throw it into a big tub of water (a lake or pond would work perfect and save changing water here), fully submerged (that 4lb porcelain base will work perfect here to hold it down). Every 1-3 days (depending on how tannis is leaching) empty the water out and replenish with fresh. You'll know when by the colour of the water.
If you want to use salt in any of these processes for curing your driftwood ... you'll have to do some research. I personally have never used the salt method, but have read where people have. Added benefit = I've no idea and won't comment. But it seems to work as well.
Now depending on how the driftwood is leaching, looking and its size, plus bouyancy. You could be soaking this for a while now. Remember your driftwood was fully dry, so this could take longer than most. I made sure my driftwood sunk to the bottom, before I used it. Although larger pieces take that much longer. (I had one piece that I considered iffy ... but it's managed to stay on the bottom unassisted.) So some people have to weigh them down anyway, for this reason as well as some want the tannis.
Note to consider, as some people prefer tannis in there tanks (its what makes your tank water look like tea). Whether you want it or not, will also determine how long and how many flushes of water you do, while soaking the driftwood to make it sink. But even after you do all this you may still end up with tannis in your tank (afterall that looks like a decent sized piece). If you want to remove said tannis, from your tank. You can always add charcoal to your filter ... actually tried it and noticed the difference. Had a tank running with charcoal in the filter, with a chunk of treated driftwood in it, for 2 weeks no tannis was present. Only took out the charcoal and maintained the same water changes, within 2 days you could see the tannis throughout the tank water.
Once this is done (the soaking part) now you want to sterilize it. I've never used salt like I said. But in your case, my gut says you might want to just for overkill ... but you'll have to do the research on that one. What I did ... I share with you. For the pieces that fit ... I put them in my cauldron and boiled them for about 20 - 25 mins. Fully submerged and full boil for the 20 - 25 minutes. I'd read that 15 mins was enough .... but wanted to be safe. After that I put mine into my tank.
Now the pieces that didn't fit into my cauldron ... i had a large washbasin, where I placed the driftwood so I could scrub with a wire brush (have a few different ones for different sizes and shapes) while my wife (Alot of trust here) poored boiling water over the areas I'm working. We did this 5 or 6 times over the whole thing ... I'd keep scrubbing with the water in the basin, while she got the next jug. The final poor was more of a rinse than anything, as I held and rotated it while she poored the boiling water over it.
I now have driftwood in all my tanks (only 3 tanks ... so far). I've treated 5 pieces trying to learn, so far everything has turned out okay. (knock on wood) As for judging when each stage was done ... not much help ... just kinda followed my gut based off of all the reading I did before my first attempt. And I've only used hardwood ... I know people have talked about softwood, but I was advised away from it ... and thought best to play it safe.
Hope this helps .... I've posted things like it before, not this much detail. But there's alot of info on this site about curing driftwood.
