Originally Posted by FishyFriend1
that won't work for me... I have tried, see i have a 5 gallon hex......
If the tube is filled with water from the sink or the tank, gravity makes the suction work regardless of the size of tank. An alternative method is you can place one end of the tube over a bathtub and one end at the sink outflow and get the tube filled also. Place your thumb over the output once the tube is filled(flowing out the outher end) and place the input tube in the tank higher than the output tube. Water will begin to drain from the tank.