So I'm fairly certain that my Melanurus is a female. It's a beautiful fish but it lacks the intricate face markings and still has the eye spots on the dorsal fin. She's big enough that it's unlikely to be a juvenile. She could become a male still but I'm happy either way. She's active, fat, and always grazing on the rocks.
Also, I checked the pH on the DIY rocks again - it dropped to 4.6.…. I took a look at the probe and saw that the "bulb" is broken. This is getting returned. I just got it a couple of days ago. It was delayed by a day and, when I received it, it was hot enough I almost couldn't hold it. Not sure if the heat cracked it or if it was broken from before getting loaded in the truck but I'm not satisfied with a broken pH probe.