Just put in some root tabs a couple days ago for the first time. The next day, everything in the tank was covered with this... well... soot. Not cloudiness, actual debris, like the tabs exploded all over the place. Is that normal? I put 4 tabs in a 29 gal, and pushed them down an inch or so under the gravel. Now I have these little root tab volcanos. SO the question is: is that normal? if not, did I do something wrong? and, how the heck do I avoid having that happen in the future? Thanks!