If the heart is pumping with some degree of efficiency, there should be no retension of fluids. When the heart is weak and unable to pump all the blood received from the lungs, the blood backs up into the lungs and peripherals and fluid leak into the tissues. And/or if the right ventricle is weak the blood returning to the heart from the peripherals will backup. A stiff right ventricle wall can impede filling and abnormal pressure can cause right side dysfunction and cause endema as well.
In addition to diuretic medication there is medication that can increase the heart's pumping strength, and of benefit can be the reduction of sodium, exercise, eat little and often to maintain healthy blood sugar levels.
I had chf several years ago, and with medication, exercise, healthy eating, etc. my heart is now functioning normally, but I didn't have any water retention subsequently. Just based on your post it is difficult to assess the water retention problems going forward. It depends on how effective treatment will be to help increase blood flow so blood doesn't backup in the peripheral vessels and lungs.
Thanks for sharing, and if you have any further questions or comments you are welcome to respond. I wish your husband well going forward, take care,
Ken