No. Fountain water treatments are not designed to prevent or remove mineral deposits inside automatic water fill valves.
Aquascape Prevent for Fountains & Waterfalls helps prevent white-scale buildup on fountain surfaces, rocks, and gravel, but it is not intended to clean internal water fill valve components or prevent valves from sticking.
If your water fill valve is experiencing mineral buildup or is not operating properly, submit a request through the Aquascape Customer Care contact form for assistance. Include your valve model and photos of the problem.