I recently used 2 pieces of mopani wood (soaked for 2 weeks prior to remove tannins) and have used it in my planted 10 gallon. It has been setup for approx 1 week. The tank has Co2, and the water tested a pH of 6.6, 0 nitrate, 0 nitrite and 0 ammonia with a high Co2 of 45. My question is the mopani wood has a visible 'slime' on some of it. It isn't white like I've seen before, just slick looking. All inhabitants seem fine, just wondering if it is something to worry about.