You should look into a gravel vacuum.
Waste and left over food particles are heavier than water particles so they settle at the bottom of the tank. Removing just the top layer of water is not properly cleaning your tank and leaves vast amounts of decomposing particles at the bottom which have a negative impact on water quality.
They are cheap and extremely easy to use and greatly reduce water changing efforts. They even have the ones that hook right to your sink which drain the dirty water out of the tank and right down the drain and then with a flip of a switch it pumps fresh water right into the tank. All you need to do is add the decholorinator right to the tank.