I'm afraid the photo is not clear enough, but I may be able to offer some suggestions. I have maintained this species for several years, and my current male (I keep them as single specimens in community tanks) is now in his seventh year which is pretty good for a fish with a four-year average.
I would look at other factors before worrying over a low pH. What is the temperature? GH (general hardness)? Nitrate (this is extremely important)?
Is this the sole Bolivian Ram in the tank? How long have you had this fish? What other fish? Is the respiration rate fairly normal? This species tends to respirate slowly compared to smaller fish like tetras.
How is the tank aquascaped (plants, chunks of wood, rock, substrate material, etc)? Are there floating plants (thinking of shading the light here) or is the light bright? What is the water change schedule (frequency and volume of the tank)?
This fish does go through moods during the day. If it is refusing to feed (you may know this, but this is a substrate feeder, so it will generally take food from the substrate not the surface) there is likely something occurring.
Byron.
