Formic Acid and Screen Bottom

When using FA in my Flow Hive- do I have to ‘seal’ the bottom since it’s a screen and not solid?

Good question, Hanalei.
It depends on the delivery method and the label instruction. I only know about FormicPro, the only formic acid product available in Australia.
The correct ventilation is important. The label calls for open entrance, i.e. no reducer and at least six frames of bees. Leaving the screened bottom adds ventilation, so close it. The Flow effectively closes it by keeping the drawer in and covering the vent slots with masking tape for the 2nd generation or sliding the Corflute tray in the upper slot for the original.
Too much ventilation reduces efficacy, too little kills bees.
FormicPro is very effective, but be prepared to see some dead bees, larvae and pupae. If they’ve already been injured by mites, they can succumb to the acid.

Mike

That’s the information I needed! Thanks! I assume I have the 2nd generation hive since I’m unaware of an upper slot for the tray. I’ll duck tape the vents!
Thank you!