Sad subject for a Friday night...apologies. It's only a year and a half old but gets loads of use (large family). I cleanit regularly, about 3 x per week whilst in shower with shampoo and sponge and once a week with cilit bang, bleach and mr muscle. I can't get the black mouldy stuff off the corners though or from the sealant. I've tried bleaching and then a toothbrush (hard to manoeuvre in corners) and a scrubbing brush. It's driving me demented.