Apologies if this isn't posted in the right place but I'm a bit stuck on what to do - and I don't want my fish to suffer.
I have a Aquanano 30 tank that's been set up for about 8 months now - the other night at about 3am out of no where it started to make a rattling sound - I switched on my light to find air bubbles shooting into the tank.
I looked and the water level at the back had dropped leaving the filter half out of the water - I moved the filter down to stop the bubbles. The next morning I got up and topped the tank up and put the filter back in place.
I turned the filter on and immediately noticed the water at the back dropped - and the air started shooting out again.
I've opened the filter up and cleaned it - done everything possible with it - but the second the filter is on the water drops and the air problem starts.
I want to make sure the tanks filtered properly.
Can anyone help?

Hi and welcome,

When the water level drops, where does the water go? Try and see where it's leaving the tank and trace back to find out what's causing it. It may be something very simple like the angle of the filter outlet. If it's pointing upwards it could be shooting the water over the top edge of the tank, or up into the lid where it then trickles down and out over the tank edge. A minor adjustment to the angle of the outlet or filter position may be all that's needed to stop this