I redid all of my ball pythons enclosures within the last year or so (with the help of the advice in this community!), and all but one of them are doing great with the improvements in humidity that their new substrates are bringing them. One of my ball pythons (Clyde) however, seems to get scale rot very easily even when I go to the low end of the ideal humidity range.
For context, I adopted him when he was about three from a situation with less than ideal husbandry. The enclosure was far too small, had only a single heat mat for warmth, and a singular hide right in the center. It also had cocoa coir substrate that was damp to the touch. He came to me with the beginning stages of scale rot, as well as some other issues that were clearly related to this subpar husbandry.
When I first got him the general substrate recommendations for ball pythons included Aspen, which was the easiest for me to get at my local pet store. I figured a dryer substrate would be better for him while he recovered from scale rot, and since he was doing well on it I didn't update it until I realized (thanks to this sub) that Aspen is no longer recommended. My snakes were due for a enclosure refresh around this time anyway, so I went ahead and switched them to a mixture of coco coir, sphagnum, leaf litter, and cyprus mulch.
My other ball pythons have done wonderfully on this substrate and their enclosures are usually around 60% humidity. I noticed Clyde began showing beginning stages of scale rot once again. I know he wasn't sitting directly on the bedding, because both of his hides have a solid base to them that the bedding was not in. I would also only pour water into the corners of the enclosure and not throughout the whole area.
I have experimented with a variety of humidity ranges for him over this past year, and anything above about 50% seems to trigger the reappearance of scale rot. I'm unsure if there is any medical reason for something like this or if it's just something unique to Clyde. As of right now I've been maintaining his humidity at about 40% and just making sure to provide a humid hide option and plenty of water when he begins to look pink-ish at the beginning of his shed cycles. This is also what I did in the years before switching him off Aspen and he never had any issues shedding then.
Has anyone experienced something like this before? Is there something I'm missing? I know too low of humidity can cause respiratory issues so I would love to get him in a more "ideal" habitat, but I also dont want to cause scale rot.
Pic of the goober as thanks