>I have a recovering hive in a 5 frame nuc, and this last brood cycle seems to be filling the nuc pretty well. I'd like to give them back the rest of their frames but don't want to do so too quickly.
If the nuc is full of bees you need to give them more room before they decide to swarm.
> Plus I want to give them an Apiguard treatment as I have seen some DWV bees and spotted a few mites on bees.
Do a sugar shake or some other method to quantify the problem. If you actually think you need to treat, then I'd also requeen. No point perpetuating bees that can't handle the mites.
> Which begs another question - if I need to keep them in the nuc until stronger can I give them a half dose of Apiguard?
I've never used it, but I would assume that volume is the issue. You want to fill the volume with vapor, so a half does makes sense.