Hi All, I don't have time to follow every chat group, but I got a notification about this one. I'm interested in your experiences with OA/gly in NZ, so please feel free to contact me directly at email@example.com. >From a practical point of view the Hive is very tolerant of high doses of OA/GL that do not go as far as to wet the Bees That is also my impression. For a strong colony, 9 g total OA in glycerin on towels did not give great mite control. But neither did 40 g (4 strips) of the Argentine formula in double-deep hives. But 80 g total did when applied in hanging strips. But the mite control was no better than 18 g OA delivered on towels with the right OA: gly ratio. It's clear that there is a substantial margin of safety for OA between what is needed to kill mites (very little), and the amount that will cause adverse effects to the colony. What appears to be most important is how quickly the OA is delivered to the bees' bodies (via the "wetting" of the bees by the glycerin). And that appears to be a function of the ratio of OA to glycerin. As Philbee said, the key balance to reach is enough delivery of OA over time, but not too much. With the Argentine 1:2 ratio (1 g of OA to 2 mL of glycerin), the acid appears to get distributed too quickly, causing jittery bees and sometimes brood kill. This does not appear to be a problem with the 1:1 ratio. Since I've found that 18 g of OA/hive results in very high efficacy in my climate, I see no need to apply a greater quantity. The thing to keep in mind is that some OA will remain in the cellulose substrate (the staple, strip, or towel), so that amount does not count towards the 18 distributed grams.