Pool Return Inlets
The Hidden Key to Perfect Water Balance
In every infinity or zero-edge pool, the stillness of water is never accidental.
It results from decades of refinement — and from invisible details such as the positioning of the pool return inlets.
At Morana Water Design, we have been integrating floor-mounted return inlets for over thirty years, long before this practice became a recognised standard in contemporary pool design.
Because when the water appears perfectly still, it is the sign of a system in balance — a balance created by precision.
What Is a Pool Return Inlet?
A pool return inlet, sometimes called a return jet or inlet fitting, is the point where filtered water re-enters the swimming pool after passing through the filtration system.
These fittings are small, discreet, and often unnoticed — yet they determine how water circulates, how debris moves, and how evenly chemicals and temperature are distributed.
In most traditional pools, returns are installed along the walls, directing water across the basin to send dirt toward the skimmers placed on the opposite side.
This horizontal circulation works efficiently for pools equipped with skimmers, where the goal is to capture floating debris.
In overflow pools, however, the logic is entirely different: the surface is continuously renewed by the overflow itself, so the goal is no longer turbulence but tranquillity.
Every movement of water must be precisely controlled to preserve the mirror-like surface that defines an infinity design.
Understanding how water re-enters the pool is only one part of a larger hydraulic picture.
You can discover how all these systems connect in our Infinity Pool Construction Guide
Wall Inlets vs Floor-Mounted Inlets
Most conventional wall return inlets are equipped with a front water outlet, designed to project the flow horizontally across the pool.
When such fittings are placed in the floor, the jet simply rises vertically, creating turbulence without improving the overall circulation.
True floor-mounted return inlets, on the other hand, have lateral outlets that direct water along the pool floor before it naturally ascends to the surface.
This sweeping movement allows the system to clean the basin floor while ensuring a steady upward flow that feeds the overflow edge evenly.
It’s a small mechanical difference, yet it changes everything: the way water moves, how sediments are lifted, and how the surface remains calm.
Even today, many pool builders and technicians who seek our advice around the world remain reluctant to adopt this configuration — not because it fails, but because it demands precise hydraulic design and exact calibration.
It also requires a more complex installation.
Floor-mounted return inlets demand perfectly levelled piping, accurate flow balancing, and — above all — flawless waterproofing.
The entire network is embedded in the structural concrete, meaning that every pipe, junction and fitting will be permanently sealed within the slab once the pool is poured.
Any imperfection at this stage could lead to leaks that are impossible to repair later.
For this reason, every connection must be checked, secured and pressure-tested before concreting.
These precautions require time, precision and experience, but they ensure absolute reliability — a non-negotiable condition in high-end infinity pool construction.
Morana's advice 👇
Get expert hydraulic design from the outset
In infinity pools and zero-edge pools, circulation defines the surface.
Our team analyses your project early and designs the entire hydraulic system — from return inlets to filtration — so the water remains quiet, balanced, and efficient.
Speak to us before any specification: we’ll ensure a system that’s both high-performing and invisible.
Discuss your project !
The Geometry of Stillness
In overflow pools (with perimeter or infinity edge systems), the placement of pool return inlets is crucial.
While many systems still rely on wall-mounted fittings, our experience has consistently proven that floor-mounted returns deliver far superior results — both technically and visually.
By introducing the flow from below, the water rises evenly toward the overflow edge, sweeping fine particles upward and eliminating stagnant zones.
The entire volume circulates harmoniously, producing a constant renewal that keeps the surface pure and silent — one of the key advantages of infinity pools.
This concept, later confirmed by the 2012 Pool & Spa News article “Circulation from the Inside”, had already been part of our design method for decades.
We were among the pool designers to position return inlets in the pool floor, understanding that the direction of water defines the geometry of the surface.
Morana Water Design pioneered the use of floor inlets in overflow pools — a principle now widely adopted across the industry.
Designing the Invisible Flow
Each pool return fitting is calculated and drawn with architectural precision.
The number, size and orientation of the inlets are adjusted to the basin’s dimensions, the hydraulic resistance, and the type of overflow — infinity, zero-edge, deck-level, or knife-edge.
Even a slight variation in flow rate or pressure can disturb the stillness of the surface.
That’s why every return is carefully positioned on the technical drawings and its hydraulic performance verified through pressure testing during installation.
This engineering discipline ensures that water moves silently, evenly and economically.
The outcome: perfect circulation, optimal filtration efficiency and reduced energy consumption.
To understand how these parameters are integrated into our technical plans, visit What Is a Pool Filtration Drawing?
The Link with In-Floor Cleaning Systems
In high-end designs, floor inlets are often combined with integrated cleaning systems.
Unlike traditional circulation, these in-floor jets do not push debris toward the main drain — they lift and suspend fine particles within the water flow.
As the jets operate in sequence, every area of the pool floor is swept, keeping the entire surface in motion and preventing sediment from settling.
The suspended particles are then captured by the filtration circuit through the overflow system, leaving the pool perfectly clean without manual vacuuming or visible equipment.
This principle, similar to systems such as Fluidra Net’n’Clean, ensures that the floor is active at 100 % of its surface — no stagnation, no residue, and a perfectly clear mirror effect.
Learn more about this approach in An Overview of Pool Cleaning Systems
Morana’s Insight – A Precision Legacy
For us, hydraulics and architecture are inseparable.
A pool’s beauty is not defined by its tiles or its lighting, but by how the water behaves.
Every inlet, outlet, and overflow channel must work together to express one idea: stillness in motion.
“We design the hydraulic balance of an infinity pool with the same care an architect draws a façade line — because water, too, has geometry.”
After more than thirty years of design and technical development, we know that perfection on the surface is born from precision beneath it.
Floor-mounted return inlets are not just a technical choice; they are a design philosophy — the silent mechanism behind visual harmony.
Pool Return Inlets – Frequently Asked Questions
What is the difference between wall and floor return inlets?
Wall-mounted returns create surface turbulence that disrupts the infinity edge effect, while floor returns generate gentle upward flow that maintains perfect stillness. Floor positioning also eliminates dead zones and provides superior debris management through reverse hydraulics.
Can pool return inlets be retrofitted to existing pools?
Converting wall returns to floor positioning requires significant structural work, including new piping and pool floor modifications. It's technically possible but complex. Floor returns are best integrated during initial construction when the hydraulic system can be designed as a unified network.
How do floor returns improve heating and chemical distribution?
Floor-mounted returns create upward thermal currents that eliminate temperature stratification, ensuring even heat distribution throughout the pool volume. The same upward flow pattern provides superior chemical mixing, eliminating cold spots and preventing localized chemical concentrations that can affect water balance and swimmer comfort.