Okay, thankyou.
Listen to this crock of bull****!
I went to an LFS (the ones that were rude about bio-spira) and I asked him for antibacterials.
He asked me what I was treating, and I told him and he said, "Columnaris, that's a fungus caused by carbonated hardness too low (or high can't remember). In order to catch a fungus, your pH has to be slightly acidic, so check pH and raise it."
He then went on to say, "Yes I have antibacterials, but you don't need 'em." and then walked off!
He refused to sell me them! He's VERY misguided! I swear i'll never go there again!
O btw, the pH is 7.4!!! Which is slightly basic!
What a dumb***!