I have a couple pieces of Malaysian drift wood in my 20 gal. fresh. I soaked and boiled them prior to putting in tank about 8-9 months ago. Nowadays, when I remove it to rinse occasionally (in dirty tank water) I get lots of debris off it and small pieces of wood. So question: How long does Malaysian drift wood last in an aquarium before it should be replaced? What type of wood is actually BEST for an aquarium or will last a long time? (I use no CO2, ferts or chemicals.) Thank you.