I have to say I'm pretty disappointed with BackyardHive. I bought into all the kumbaya "bee-guardian" malarkey and ended up with the varroa mite infestation from hell. Three separate requests for help were completely ignored, but they're always there when you have money to spend. A late August alcohol wash yielded 16 mites/100 bees. Autopsies on drone comb revealed mites in every cell, sometimes up to 4 mites in a single cell. It was nuts. We tried using hop-guard II to save the hive, but the bees absconded and that was that.
I mainly blame my inexperience being a first-year keeper. However, I also blame the design of this hive. There is no way to treat for mites, should you decide to treat for mites, because as far as I can tell, the designers deliberately designed it that way.
I pulled the hive down in to my shop and cut out the bottom and installed a new bottom. I cut two holes, instead of one long one, to preserve the support installed in the middle of the hive base. I routed a 1/2 wide by 1/4 deep groove and tacked #8 hardware cloth into the opening. I put a frame on top of that to secure everything. I attached a new bottom to the supports. That gave me enough space to slide in two drawers; one under the brood and another under the honey. The drawers can accommodate sticky paper, diatomaceous earth, or MiteAway strips.
Yes, I know, I could have drilled a hole and installed a port for an oxalic acid vaporizer, but this was the route I chose to go. Bees arrive 4/22. I hope this works. At least this year I feel like I can do something to treat instead of just watching helplessly as varroa decimates a colony.