My tank was finally doing well, algae under control, fish and snails happily living together, perfect water chemistry....so I decided to try adding co2 to get some better plant growth. I also added some plants that grow better with Co2. I watched several videos and read articles about Co2, pros/cons and set up. I bought the Ista professional system, with solenoid and timer. Set it up on Monday, it worked fine, turned off overnight, Tuesday and Wednesday, Co2 levels were good, it turned off overnight. Thursday morning I left for work and it was at about 1 bubble every 3-4 seconds and microbubbles had started to come in. I left for work, all was well. I got home that evening, went to greet my fish and they were all dead, and my snails were not doing so hot. Co2 tank was empty and the indicators were yellow. I feel horrible that I upset my tank balance and killed my finned friends!! What did I do wrong?!? My snails recovered and are back in that tank. I really want to learn from this mistake so any insight on what may have happened would be appreciated.
Thanks!