Mould often appears in grout lines due to their porous nature, combined with trapped moisture and inadequate ventilation. Black stains on tile grout can make a bathroom appear unclean, even after deep cleaning. Natural remedies like white vinegar and bicarbonate of soda often fall short. A hands-on test compared three popular mould removers—HG Mould Spray, Astonish Mould Blast Stain Remover, and Mould Magic—to determine the most effective option for tile grout.

Products Tested

Astonish Mould Remover costs £1.99 at Wilko and The Range or £2.99 at Lakeland. HG Mould Remover is available for £4.29 at Savers or £6 at B&Q. Mould Magic gel, sold by Must Have Ideas, retails for £12.99 for two tubes and promises to eliminate 100% of mould in one application.

Testing Method

The grout showed black, brown, and yellow stains, worst near the shower. Each product was applied to separate areas on dry surfaces, with gloves worn for safety. Mould Magic gel applied thickly, adhering well without dripping or strong odour, but required 2-3 hours to work. HG Mould Spray foamed up, clinging to grout despite some runoff, and needed 30 minutes; its bleach-like smell was strong but manageable with ventilation. Astonish spray, the most liquid, was left on for 10 minutes despite running off quickly and having a noticeable scent.

Results

Astonish surprised by wiping away mould cleanly in one pass after 10 minutes, though grout wasn’t perfectly white. HG removed stains effortlessly after 30 minutes, with a quick rinse revealing bright white grout. Mould Magic eliminated all mould but left a stubborn gel residue on tiles, requiring careful wiping.

Verdict

All three products effectively tackle grout mould. HG Mould Spray stands out for its 30-minute action time, superior penetration, and bright finish on grout. Astonish offers quick, budget-friendly results at £1.99, ideal for light stains. Mould Magic excels on sealant but takes longer, leaves residue, and is harder to source.