I am making some plans for mite treatment while the Snelgrove boards are in place - figuring that will likely be needed though I haven't yet tested for mites. Anyone have a brilliant solution for this? The bottom section, below Snelgrove, is not a problem as it's almost completely brood free early on. The top, where all (almost all) the brood was placed, will need treating. I don't think an OAV from the bottom is going to work; the OA would have to travel through the bottom box, supers, Snelgrove screens, and on its way is likely to crystallize out before reaching the areas that most need the treatment. But the Snelgrove door is not large enough to accomodate a Varrox, which is what I have. I don't know - maybe Formic Pro would be the only other option when it warms up a bit.