The water from my tap is 7.2, I did not have a ammonia problem it was a bogwood problem. I had already 2 small pieces of it in the tank and held a steady 6.6 level. I purchased another in hopes to attach pheonix moss to it(which I have not found any yet). In any case I only soaked it in very hot water for a couple hours and eagerly put it in my tank without a second thought to the tannins(which I knew nothing about at the time, because I did not do any research,not thinking it would upset my ph so badly. So out came the wood! No rotting fish,except for the danio I found in my storage basket,poor thing. I have also considered the change of the level of my ph to have some effect on my gourami,it was extremely low 5.9-6.0. So far it has not effected my other 2 gouramis,but I am keeping a close eye on them. I use a penguin bio-filter 150 for my 29 gal. tank and have 2 filter mediums inside. I moved my female gourami into my hospital tank 4 days ago and have started treating her. The other female and male are not the same with her gone,but hopefully soon they will all be reunited.
