white fog between double pane windows

Nope, they have to be replaced or properly repaired. Repaired means the sash must be disassembled, cleaned on the inside, re-filled with Argon and re-sealed. Depending on the window size, of course, most repairs around me cost $75 to $150 Per Sash and they last for decades.

- However, replacement may be an option for you, if you have stock-size sashes. I've had only some luck with this. But, if your sash matches the dimensions, including thickness, of a Home Improvement stores off-the-shelf window, then buy it and pop them in your window. In my few cases, the Support Balances were just screw-on, but a deal breaker if yours aren't.