A rubber pad is the first thing to try.

Yes, it can make a surprising difference. Most pool pump noise is vibration being transmitted through the concrete or pad it sits on. A thick rubber mat or anti-vibration pads under the pump feet decouple that vibration, dropping the noise noticeably without touching performance.

Check a few other things while you’re at it: loose pump cover screws, a cracked base, or debris rattling inside. If the pump is old and hums loudly even after isolating it, consider a variable-speed pump — they’re quieter, more efficient, and pay for themselves in power savings.

Don’t buy a new pump just yet. Start with the $20 fix.