solid bottom board

Hello, I have 2 hives that I started last year. During last year I grow from 1 deep to 2 deeps and went through the winter well. Both hives did very well and even better - they were so strong so they swarmed. Once I saw that hives did the winter well, I put 3rd deep on top hopping that they...

Which do you prefer and why? Thanks in advance for your replies. :)