Space solves: A low bookcase, plus where can I buy oxygen bleach?

I need a low bookcase to fit under a window – max height 75cm. Even Ikea has nothing in its brochure. Here are five to choose from: Porto four-cube long storage in black or white (H: 48cm x W: 155cm x D: 35cm), £149, from Dwell ; Library unit in Douglas fir by Michael Marriot (H: 41cm x W: 63.5cm x D: 21.5cm), £155, from SCP ; Massello open wall unit in oak and oak veneer (H: 64cm x W: 128cm x D: 30cm), £219, from Habitat ; Occa shelving long in walnut veneer (H: 44cm x W: 183cm x D: 30cm), £383, from I-Furnish.com ; Bakota low shelving unit in Paulownia wood (H: 70cm x W: 180cm x D: 40cm), £399, Habitat, as before. Our wood decking needs cleaning. I've been recommended powdered oxygen bleach as it cleans well and is nontoxic. Where can I buy it in reasonable quantities in the UK? "An excellent nontoxic choice," says our cleaning expert, Stephanie Zia. "When sold in bulk, oxygen bleach goes under its chemical name, sodium percarbonate, and it's quite hard to find. The Irish company Mistral Cleaning Products sells a wide range of environmentally friendly, biodegradable specialist chemicals, from ecofriendly drain cleaners to nontoxic carpet cleaners. Sodium percarbonate costs from £4.78/250g to £47.84/10kg. You probably want something in the middle range. The cost for 5kg is £38.26, including VAT and postage to mainland UK as well as Ireland ." • Got a question for our crack team of domestic experts? Email [email protected]