Hot tub cover care

1. Hose the top to loosen dirt.
2. Scrub with a soft brush or sponge and mild soap. Hot Spring's mix is four tablespoons of mild soap in a gallon of lukewarm water.
3. Keep the seams closed if the cover stays on the tub, so soap can't run into the water.
4. Rinse well and don't let soap dry on it.
5. Rinse the underside with water only. Hot Spring and Jacuzzi both say no soap on the underside.

Skip solvents, abrasives and products with silicone or alcohol; Jacuzzi lists all four. Hot Spring adds: no plastic tarp or metal object on the cover, which can melt the foam core.

The makers differ on the underside. Master Spas says a bleach and water mixture on a soft cloth may be needed for mold or mildew stains, rinsed thoroughly after. Hot Spring and Jacuzzi say water only underneath. Check your cover's own tag: Master Spas notes the cover warranty often comes from the cover maker, not the spa maker.

Prevention comes down to airflow. Leave the cover open 15 to 20 minutes after adding chemicals so the off-gas doesn't collect underneath. If the tub sits empty, Master Spas suggests a 1-inch block of foam between cover and shell for ventilation.

• Brush off snow; its weight can break the foam core.
• Don't sit, stand or walk on it, or lift it by the flaps or straps.
• Lock the straps every time; CPSC advises a locked safety cover whenever the tub isn't in use.
• Use a cover lifter, or keep it off the ground and off wooden decks, which chemicals can bleach.
• Don't put the seam over the control panel; Jacuzzi says it shortens the control's life.

For thickness, taper and what to look for in a replacement, see hot tub covers.