Hi. This is my first public video on my Oscar tank :-) . This video is about how I did an aggressive water change because of high , ammonia , nitrate , nitrite levels. The fish where show signs of distress , heavy breathing, poor interest in food and very sluggish in their movements. I bought this tank and fish on an online auction so I didn't know that real state of the tank till I went to make pickup. Used phone to do the recording so quality is not the best.