5. Soap scum on the bath, tray and tiles
Soap scum is not soap. It is the reaction product of soap’s fatty acids with the calcium in hard water — an insoluble, sticky film that ordinary detergent barely touches and that grabs skin cells and dust.
The treatment is two-stage again, and the order matters. Spray a degreasing cleaner or apply a paste of bicarbonate of soda with a squirt of washing-up liquid, leave ten minutes and scrub with a non-scratch pad to break the fat component. Rinse. Then apply an acid cleaner for the mineral component, leave fifteen minutes, scrub lightly and rinse thoroughly. Doing acid first simply bounces off the greasy layer.
On acrylic baths and shower trays, avoid anything abrasive. Scratched acrylic goes dull and then holds scum far more tightly than it did when smooth, turning a cleaning problem into a permanent one. Non-scratch pads and time are the right combination.
The long-term fix is to stop making scum. Bar soap is the main culprit, because it is the fatty acid content that reacts. Switching to a liquid body wash or a syndet bar — a synthetic detergent bar — reduces the film dramatically in hard-water areas, and most people notice the difference within a fortnight. Rinsing the bath or tray with the shower head after each use, then wiping with a microfibre cloth, keeps the rest from building.
Reduce shampoo and conditioner dilution too; excess product rinsed onto surfaces feeds the same film.