Some buyers say it matches their Alexa to within half a degree. Others swear it reads ten degrees too warm. We went looking for what separates the happy owners from the furious ones, and found the answer has less to do with the TP49 than you might think.

Pour it in, run the pump, wait 24 hours, sparkling water. That's how most owners describe this £7.99 bottle. So why do roughly one in six reviewers say it did absolutely nothing? The answer is hiding in the five-star reviews.

A 150-strip pack for under a tenner that several owners say reads their hot tub more accurately than the brand they used before. That claim deserves a closer look, and so does the one buyer whose strips kept misreading plain water.

At under a tenner for a 5ft Saltire, the AhfuLife flag is the kind of buy you make without much thought. The reviews suggest you should give the small print a second look first.

<p>This is the small grey-and-red fitting that ends up on the business end of half the hoses in Britain. We read through dozens of owner reviews from across Europe to find out whether the Hozelock soft touch end connector deserves its near-permanent place in the shed, and where buyers reckon it lets them down.</p>

At £11.95 for a 2m x 10m sheet, this ANSIO membrane covers a lot of ground for very little money. The catch sits at the moment you reach for the scissors, and it shapes almost every review worth reading.

A badger named Ralph approves, the woodpeckers approve, and one squirrel came through the cat flap for more. Yet the buyers on their 30th tub are hesitating. What 100 recent reviews say about Garden Ting's 5 litre peanut tub.

A windfarm crew in the remote Highlands and a horse fly in a Greek valley that visibly changed its mind about biting: Smidge reviews come from memorable places. The pattern in them is geographic. This picaridin cream is brilliant against British biters, and more of a coin toss against tropical mosquitoes.

Where you hang this £9.49 saltire matters more than anything else about it. The same four brass corner eyelets that make it the easiest flag to mount on a fence or wall sit at the centre of its unhappiest reviews, so picking the right spot is most of the decision.

One buyer has bought these strips for five years and never had a problem. Another found no chlorine in water their other strips called perfect, then turned the pot over and saw the use-by date rubbed off. With Clearwater's 3-in-1 strips, the argument starts at the bottom of the pot.

Sanitise, stabilise, kill algae and clear cloudy water with one floating tablet. We dug into what UK pool and hot tub owners say about Clearwater's £15 tub, including the one complaint that keeps recurring.

An above-ground frame pool at under a hundred pounds sounds like a steal, and for a lot of UK families it is. But 24% of the most recent 100 reviews give it one star, and almost all of those one-stars share the same complaint. Here's what the divergence means before you click buy.