The Congo tetras for anywhere from one and a half to 2 1/2 inches in I was running a fluval 407 filter. Again, I don’t really think the Tetris were sick since they were eating just the day before and they were very active that night. I do intend on eventually making a 270 gallon pond in my house for the bichirs. If you have any suggestions on what I can do for that it would be greatly appreciated. Unfortunately, it won’t be happening for another 1 to 2 years but I am open to any suggestions.