Answers
A page for each question, answered before the first full stop
49 questions, one page each, with the answer in the opening sentence rather than after four paragraphs of preamble. Where the honest answer is that the published figure was taken under conditions your garden will never see, the page names those conditions and goes no further.
Choosing
Which piece of equipment answers the need at all, when the cheapest option in a family is the right one, and what a private pool does not need.
Flow & turnover
What a flow rate in litres per hour means once it is divided into a pool, how long a full turnover should take, and why head changes the answer.
Sizing & volume
Why a stated volume is not the volume of the pool, how freeboard is counted, and what the difference does to every chemical dose.
Hoses & fittings
Why 32 mm and 38 mm do not interchange, what a stepped adaptor costs in flow, and which thread a pump and a filter actually share.
Water chemistry
What pH does to chlorine, why a pool can read chlorine and behave as though it has none, and which figure the strips do not show you.
Disinfection
Chlorine, bromine, active oxygen and salt electrolysis: what each one is, what each one costs to run, and what each one gives up.
Filter media
Sand, glass and cartridges compared on fineness, bed life and the cost of a season — and why a media change is not a like-for-like swap.
Heating & covers
What a COP is quoted at, why a cover is the cheapest heating on the site, and how much energy one degree in ten thousand litres really takes.
Cleaning & robots
Runtime against the surfaces it is spent on, what a filter fineness in microns catches, and which pool walls a climbing robot cannot hold.
Installation
How flat the ground has to be, what goes under a liner, where backwash water goes, and which fixings a wall fitting needs.
Winter & storage
Why a pool is not emptied for winter, what a winter pillow is actually for, and which parts have to be drained before a frost.
Maintenance & wear
The one part per family that goes first, whether a spare exists for it, and which products were built to be replaced whole.
Spas & hot water
Why bromine holds where chlorine does not, what a heat-up rate means in practice, and how a spa differs from a small pool in every respect that matters.