I finally had to replace my filter. The 4x20x25 is not a true measurement. The new filter is lose, short , and is not 4 but 3.5 wide. If I was building anything with your measurements. Everything would be ugly.
I just started using your product, so it's too soon for me to evaluate it. Get back to me in 4-6 months when I've had time to use it and see how the filter works.