I'm sorry to hear that your first round with the Formic Pro pads didn't achieve your goals. As written earlier on this thread, I did a FA treatment on August 30th and a month later, my hives showed a zero mite load (alcohol washes) and have fully recovered. I did the two pad treatment which had a predictable die off initially, and yes, at first I thought the worst (being a new beek) with a week of several hundred dead bees being ejected form the hive. The bees that died off were infected, sick and would have not only died anyway, but would have continued the infections until the entire hive died off. Keep reminding yourself that in a double deep, there's at least 40,000 bees that you're saving. A month out, I have lots new bees doing orientation flights, loads of brood and an activity that makes me think the bees think it's May. In my micro climate here, they are bring in loads of pollen and nectar, so much I'm wondering where they're putting it! The hives are heavy and I don't see any need to feed for at least another month if at all. Our weather here looks like low '70's highs with low 50's at night, still have a lot of goldenrod and aster going and still budding out.
End of my story is that FA is a very strong treatment-if you follow the directions (read the manufactures web site) it works and is now a part of my IPM plan.