Calcified water deposits.

Why mineral deposits form on courts

Indoor pickleball courts aren't supposed to get wet. When water finds a way to the surface and sits long enough to evaporate — even slowly — it leaves behind everything that was dissolved in it. In municipal water, that's mostly calcium carbonate plus magnesium, sodium, and trace minerals. The visible result is a white or off-white haze that builds up in the same pattern as the water source.

Common sources we see:

• Ceiling leaks. A pinhole in a pipe above the court drips on the same spot for weeks. Each drop carries minerals that stay behind after evaporation.
• HVAC condensation overflow. Condensate pans on HVAC units mounted above courts can overflow when the drain line clogs. The overflow is mineral-rich and evaporates on the court surface below.
• Roof seam intrusion. A slow leak through a roof seam during winter freeze-thaw cycles drips into the building when temperatures rise. Visible as a vertical band of deposit if the leak migrates down a column.
• Sprinkler test residue. Annual fire-system flush tests leave standing water on the floor below if the test isn't properly contained. Aged piping in particular carries heavy mineral load.

Why normal cleaning doesn't lift the deposit

Calcium carbonate is alkaline and doesn't respond to most general-purpose cleaning agents. Janitorial outfits without specialty experience usually try one of three wrong approaches:

• Strong acid cleaners (CLR, lime-and-rust removers, muriatic). These work on the calcium but they also etch the acrylic court topcoat. You trade a calcium stain for a clean spot that's actually surface damage.
• Aggressive scrubbing with the wrong pad. Black or green pads can mechanically grind off the deposit, but they grind off the finish underneath at the same time. More on pad selection →
• Pressure washing. Forces water under the topcoat, doesn't actually lift the embedded minerals, and creates new problems.

How we approach calcium removal

• Test patch first. Court-safe, neutral pH chemistry formulated to break down calcium carbonate without affecting acrylic. Applied to a small area to confirm the deposit lifts cleanly. If neutral pH won't dissolve it, we tell you — that means the source has been deposit-building for a long time and may need a different approach entirely.
• Pre-treatment dwell. Calcium needs contact time to dissolve. We apply, let it work, then mechanically agitate with a non-abrasive pad.
• Extraction. Spent chemistry plus dissolved minerals are extracted simultaneously — no residue left to redeposit.
• Neutralization rinse. Final pass restores the surface to neutral.
• Documentation. Before-and-after photo set, with deposit pattern noted at intake (useful for correlating with the suspected source).

Source has to be fixed separately

This is important: we remove the deposit. We don't fix the leak. If the building maintenance team doesn't address the underlying water source — the leaking pipe, the overflowing condensate pan, the roof seam — new deposits will form in the same pattern. Our intake documentation helps the maintenance team identify where the water is coming from based on the deposit footprint.

What we can't do

If the calcium has been there for years and has actually embedded into the acrylic structure rather than sitting on top of it, restoration lifts most of it but may leave a faint outline. Same honest call as rust: the test patch tells us what's achievable, and if the outcome won't justify the cost, we say so.