Well bud, what do you do with the other panel that is also 20" trying to go through a 19" hole? It is 20" X 20" square. It could a 5 inch deep sump and it still wouldn't fit through the front. Pull the tank out and re sump from the back.If the sump is 20 x 20 x 15, there is a face that is 20 x 15 which is less than 20 x 19.