I have a pair of rams in a 125l community tank which has cardinal tetra, lemon tetra, corys and a clown plec. It is pretty heavily planted, and my maintenance routine is pretty strict. I introduced the female last week (after having a female die a few months ago) and i noticed the two of them building a nest and cleaning an area for spawning last night. The females "breeding tube" was extended. I have reasonably hard water, which i know is not ideal at all, i just drip acclimatised them slowly and they have been fine. My nitrates are very low due to the plants.
I run the tank at around 28*c which i know is a little on the high side for the corys but they have been fine for the last 6 months.
GBR's can be very sensitive, you will find many posts on forums on the net telling you that "they just die", and i have to say that was my experience with my previous female, one day she was fine, no obvious health issues, the next day she was dead. The male has been perfect with no issues at all. I was a little concerned that the male would be a bit funny with the new female after being the only cichlid in the tank for 3 months, but he was fine. Whilst the female was in the bag in the tank he was displaying to her and she was too. Quite amazing to watch. I will see if i can get some pics up of them in their nest.
edit: here are some pics:
Female in nest, showing nice colours:
Male joining her in the area:
Male inspecting what i am doing not looking too pleased about being disturbed (apologies for blurryness)