Nice tank! Love the UG.
Question: I got what I believe to be the same exact lace rock from my LFS, and just tonight I got around to testing it with the nitrate test fluid (one small drop of test fluid #1 on various parts of the rock). It fizzed up pretty good. Which made me decide against using it. Are you worried about it rasing the pH of the water? If not, how come? I ask because I do want to use it, I got it cheap enough and it looks pretty neat. Thanks for any feedback!