concerns

Hey I currently have a Silver arowana around 8-10 inches maybe, in a 125g tank. He has been in the tank for about 2 months now. The problem I see is that the arowana sits in the top corner of the tank all day and I only see him swim when its dark at night. I stopped turning on the light because...

Recently I stocked my 240L with two fire and ice snakeheads... i knew they were jumpers when i got them but one of my new guys just loves to ride the bubbles from the airstone and jump into the lid! So the question or thing im wondering is should i be concerned that hes gonna cause himself some...