Yep. Tank was almost cycled (fishless cycle with ammonia). This Saturday I did a LWC (large water change) with bottled Bisleri and ran some WP tests ( water parameters) and found out nitrite going off the charts (toxic to fish) while before lwc all was great! I was stunned. Then I tested Bisleri to only discover it has toxic levels of nitrite! (toxic to fish). Bewildered me did more tests and the conclusion is my tap water is safest for fish! So did another 30% wc, now waiting for parameters/cycle to finish as I type this. Decor can be changed anytime. Can't think of anything better right now. Been on this project since mid April (lots of trials and error to almost perfect this type of filtration: Anoxic Filtration system Dr. Kevin Novak)