I have a pair of common BNs in a 20 gallon tank. This is my first breeding attempt. I had a group of 5 and have picked out the nicest male and female. So they have been alone together as a pair for a bit over 24 hours now. I notice a big behavior change immediately. I had never seen a pleco "fan" but the male is doing it all over! On the cave, in the cave, and on the glass! I've even seen him swim over to the female, stop right in front of her, and start fanning! so funny! Is this flirting? It sure looks like it!