[HopDen]

So I was sanitizing 5 kegs today with idaphor. As usual the water (tap) turns an expected reddish color. After recirculating the solution through my bucket blaster on keg #4 I noticed that the color had dissipated and the water was nearly clear. Does the idaphor lose its sanitizing abilities the longer it recirculates? I didn't want to take any chances so I added more idaphor.

[Bob357]

Iodophor solution does lose its effectiveness over time. Recirculating increases the speed at which it degrades due to the greatly multiplied exposure to oxygen.

[BrewBama]

+1. By aerating it, you are speeding up the normal gradual inactivation. Basically, the iodine is driven off as a gas.

[Fire Rooster]

My first guess, surfaces were very warm/hot.
If it was freshly made Iodophor using COLD water, and it contacted
hot surfaces, the Iodophor was deactivated.

I saw the same issue when using Iodophor with bottles that were
still hot from being rinsed with hot water.  I now wait until surfaces
rinsed with hot water cool down, or final rinse with cold water before
using Iodophor.

[HopDen]

I was thinking along those lines. Aeration is degrading the effectiveness. Thanks!

[hopfenundmalz]

Iodaphor solutionn in an open bucket will lose effectiveness in a day or two. The iodine diffuses into the air, you can smell it. Pro Brewer friends will make a fresh bucket on brewday.