I'm adding a second hive this spring. The first hive is on a few cinder blocks and I like having it a little off the ground. I plan on placing the second hive near the first and would like to put both hives on planks running between cinder block risers, leaving space between the hives to place supers while I inspect, etc. I'm thinking of getting 6 1/2 foot planks so that I can comfortably place a hive near each end leaving a couple of feet in between. Any thoughts on this plan? Is the spacing adequate? Should I worry about drifting or robbing? I've read a little about marking hives with geometric designs or colors. It sounds intriguing but does it really matter?