I buy a dw from my LFS
before 2 week from now. Its 1ft in length almost. I started to keep soaking from that day and every 12th hr in the day I changed the water.at the begining it released higher level of tanin.bt as days passed water level become less cloudy. I kept doing this almost 1week and the last day before putting it in my tank I scrub it wid a steel wool gently and then keep in salty water for few hour. Now its in my tank and all fine wid me. Add carbon in my filter the day I keep the dw in tank.