Since spoilage tends to occur at the ends of these feeders, add Feeder Fresh to those areas as you add seed.
For Tube Feeders
Pour a one inch layer of Feeder Fresh into the feeder before seed. Or, if the feeder ports are at the very bottom, create a two-inch layer with a 50/50 mixture of seed and Feeder Fresh, then add seed.
Each time you refill your feeder with seed, add 1/4 inch layer of Feeder Fresh on top
Disinfect your feeder and replace Feeder Fresh at regular intervals depending on weather conditions. If moisture problems persist, add more Feeder Fresh to your feeder, or replace it more often