I have a piece of drift wood in my cherry shrimp tank that has tiny white soft spots on it. the shrimp seem fine and no deaths. The wood has been in that tank for 2 weeks. There is no nasty smell. When i do water changes i just brush it off and suck it out with my python. I do wather changes at least once a week 20-30%. Any ideas what it could be? should i take the wood out and give it a good cleaning? i have another piece i bought (same pet store, same time) that doesn't have had as much white spots on it:help: