THE TANK ARGUMENT, SHORT VERSION: a vanishing edge sheds its whole top layer the moment swimmers displace it, and an undersized basin hands you a pump sucking air at the dinner hour. Every Weirline tank is sized at 1.5× the weir load, arithmetic in the binder.
How an edge works
What the horizon is wearing
A vanishing edge is a one-way valve with a room behind it: the weir sheds, the tank catches, the pump hands the water back — balanced to the gallon before the shape is ever drawn. An undersized tank is invisible in the render and unmistakable at six in the evening, which is why the arithmetic comes first here and the pretty drawings second.
An edge that flickers at dusk was priced wrong at the tank, not at the weir.
Services & rates
Edges & tanks, priced from
Prices are from last season’s Salterra bench builds and cover shell through first fill on a straightforward lot; access grades, rock and retaining work are priced at the free site visit. Every package ships with the binder — tank arithmetic, pump curves, the winter logic — which is the same binder the county inspector reads.
Vanishing-edge gunite poolfrom $151,000
Shell, weir in cut stone or stainless, surge tank at 1.5× weir load, automation, coping & balanced fill
Mirror-rim poolfrom $118,000
Perimeter-overflow rim on dead-level water, slot gutter, reflection you can read a sundial in
Overflow spa, spilling infrom $44,000
Hot well with its own heat and its own edge, glass waterline, surge shared with the main tank
Surge-tank retrofitfrom $19,500
The fix for an edge that sucks air at the dinner hour: re-tanked hydraulics, level logic, re-balanced load
Automation & the level log$7,200 installed
Level, pumps, heat, spillover and chemistry on one controller — any builder’s pool, log included
The annual edge auditincluded year one
Weir clean, level calibration, water audit against the log
2025 — 2026, the bench
Edges we have built
Six from last season, photographed at the hour the weir earns its keep. Owners along the bench will show you their level log faster than their view.
How it goes
Borings to first horizon
The same sequence on every job — the only variable is your project.
Weeks 1–2
Soil, grade & the arithmetic
Borings, the fall of the lot the edge will pretend not to have, and the surge calculation against your family’s dusk habits. The binder opens here and every number that follows lands in it — the tank is sized before the shape is drawn.
Weeks 3–6
Shell & tank, one pour sequence
Excavation, steel, shotcrete for pool and tank in one continuous sequence so the structure is monolithic, then the 28-day cure — hosed, covered, on the published schedule from day one.
Weeks 7–9
Weir, finish & the slot
The weir set to the millimetre in stone or stainless, glass waterline, deck drained by the slot gutter. This is the fortnight the pool learns to lie convincingly about which way is down.
Weeks 10–11
Automate, fill, log
Level, pumps, heat and spillover on one controller; the fill, the balance, the first dusk photograph — for your file and, if you allow it, this page. The log starts writing the same day.
1.5× or the re-tank is ours
Every tank sized at one and a half times its weir load, in writing, in the binder. An edge of ours that flickers from surge starvation gets re-tanked on our invoice — it has not happened yet, and the clause is why.
The millimetre, logged
The automation holds the weir level and records it — the guarantee is checked by data, not by anybody’s squint. The log page is yours, forever, and it is boring in the best way.
The binder travels
Tank arithmetic, pump curves, winter logic, the level history: one bound book that any competent service firm in the county can run an edge from, long after we are a memory. Deliberate.
Before the dig
Straight questions about edges
The five every bench kitchen reaches once the render arrives. The yard line answers seven to six, Cinder Mesa time.
Why does an edge need a tank at all?
Because swimmers displace water and the weir sheds it — a pool party can move the whole top layer of a pool over the lip in an afternoon. The tank catches that surge and hands it back within seconds; without one, the pump drinks air, the edge flickers, and the equipment ages in dog years. The tank is not an accessory. It is the pool.
What does one cost to run?
More than a flat pool, less than you fear: the edge pump runs a variable schedule the controller writes from the level log, and the honest figure — higher in swim months, a trickle in winter — is a line in the binder at quote time, modelled on your tariff. Nobody discovers it in July.
Can our existing pool take an edge?
Sometimes, and the borings plus the grade decide, not enthusiasm. A sound shell on a lot that falls the right way can take a weir cut-in and a tank beside the pad in a season. The Ortega rewrite on this page is that job done honestly; the lots that argue, we tell you they argue.
What happens at freeze?
The controller drops to winter logic: level held, weirs trickling where a freeze demands it, heat at the floor you set, and the log still writing. The February check is a booked visit and worth the drive up the bench — it is in the binder with a date on it.
Mirror rim or vanishing edge — which?
The edge throws the water at a view; the mirror rim holds it flat so the sky and the house double in it — with a slot gutter doing the work a skimmer would ruin. Same tank math underneath, different illusion. Some lots ask for both, and the binder prices both honestly before you choose.
Fourteen for dinner, everyone in the pool at once, and the edge never blinked. I asked the physics of it and got a binder — weir load, tank arithmetic, pump curve, one and a half times the party. The photograph from that dusk is on their page and it is not styled; the horizon simply does that now.
Our 2011 edge flickered every evening for a decade and two firms failed to fix it. Weirline measured the tank, said “undersized by forty percent” inside an hour, re-tanked it in three weeks. The millimetre claim sounded like marketing until the log page: two hundred days, zero drift.
The mirror rim does the thing where the house doubles at dusk and guests stop talking mid-sentence. What sold us was less poetic: the slot gutter means nothing bobs in the reflection, and the level log means the water is identical on a Tuesday in March to the day it filled. The binder lives beside the deed.
Free site visit & tank arithmetic across the bench · (555) 014-7592 · edge@weirlinepools.example
Bring us the lot with the view
Send the address and where the horizon sits. We come with the borings file and the weir catalogue, walk the grade, and follow with a scaled concept, the tank arithmetic and a fixed quote inside three weeks — binder included. edge@weirlinepools.example