

Pyramiding is the excessive upward growth of the scutes on a turtle’s shell. As a result, each scute becomes pyramid-like in shape, or “bumpy.” This condition is more common in tortoises than aquatic turtles, but it is still a possibility for red-eared slider.
Research has proven that calcium/phosphorus imbalance does not cause pyramiding in red-eared sliders.
Pyramiding can’t be reversed, sadly, but you can prevent further damage. Read the ReptiFiles Red Eared Slider Care Guide, evaluate your husbandry, and correct any deficiencies.
References
Pyramiding. (n.d.). Arizona Exotic Animal Hospital. Retrieved November 11, 2020, from https://azeah.com/tortoises-turtles/pyramiding
Stancel, C. F., Dierenfeld, E. S., & Schoknecht, P. A. (1998). Calcium and phosphorus supplementation decreases growth, but does not induce pyramiding, in young red-eared sliders, Trachemys scripta elegans. Zoo Biology, 1, 17–24.