After having done two disappointing rounds of MAQS since August (no apparent damage to queens or brood, fortunately, but modest and only short-lived results on the mites), I decided to try a series of OAV.
I have the Varroacleaner. Bought a new battery, and gas mask for the occasion. Test-fired it and started in this morning.
On the first two hives (one with 3/4 tsp OA and one with only 1/4 tsp, due to size of colony differences) things went as I expected.
The third and fourth did not. The third one had a full teaspoon of OA. When I withdrew the wand, it and the cookie sheet it was sitting on, were covered with kind of white fluffy "snow", as if the OA had not sublimated fully. There is additional visible fluff at the far end of the floor.
I checked the battery strength thinking that perhaps it wasn't giving enough juice. It was good. Actually I didn't do the checking, my dear husband, the electrician, did; I have no idea how to use a multimeter. I also thought perhaps a whole teaspoon was too much.
Fourth hive required only a half teaspoon. The same thing happened, though less so, and with more flat flakes of OA scattered around on the cookie sheet. In this case I went to particular care to make sure the wand and cup were perfectly flat, centered, etc., so I can rule out displacement, or tipped reservoir.
Can I conclude that in the last two stacks, the full dose wasn't dispensed? I did notice that for these two, in contrast to the other two, there was only minimal "buzz-roar" during application.
On the good side, none of the colonies seemed madly unhappy during and after the treatment. It was quite cool (@ 50F) so they weren't eager to rush out afterwards. I have fresh stickies in so we'll see what drop I get.
Just would like to know if the "snow" is a problem, or simply normal ops. If it was a deficient application I can just add another one on to the end of the series for those two stacks, I guess.
The process seemed quite fiddly and time consuming, but I can see that was mostly my own unfamiliarity with the technique. I think that I will fabricate some sort of wide, flat, sheet metal base with some clips or stops to hold the reservoir in perfect position during treatment. That will save more than half the time and effort at insertion. Then one could insert, plug the entrance, light up the wand, and start the timer. And then for a minute or so, you could be preparing or ventilating another hive.
Thanks for any advice about the OA "snow" you can offer.