:rotf: Can you do that safely? I've always wondered how high I can fill my tank. I don't want to break the glass... when it says the tank is so many litres, does that mean if you fill it right to the top, or is there a specific amount of centimetres or something, you should leave at the top? Although I guess I have to allow for the filter, to make sure there is enough surface disruption of the water... but I do have a pump so there should be enough oxygen anyway.