Created by: Emma Collins
Last updated:
Compare entered NFT channel targets with measured inlet flows, manifold capacity, pump operating-point flow, reserve, uniformity, and daily circulation.
Compare a sourced per-channel target with three measured NFT inlets, manifold and installed pump flow, reserve, and timed daily circulation.
A NFT Channel Flow Allocation Calculator is a measurement-led hydroponic planning worksheet that compares a source-entered target for each NFT channel with measured inlet flows, manifold and pump capacity, reserve, distribution uniformity, and circulated volume. It exposes the entered evidence and intermediate arithmetic so operators can review an allocation or failure scenario before relying on it.
Hydroponic hydraulics link reservoirs, pumps, channels, emitters, diffusers, drains, controls, and crops. A number printed on one device rarely describes the installed system. Water-pump output falls as required head changes. Air-pump labels may state free-air output rather than output at the actual backpressure. Emitters foul, manifold branches differ, roots alter channels, filters load, and return paths may behave differently during shutdown.
It does not prescribe NFT flow, slope, film depth, oxygenation, or crop suitability, and it does not approve the manifold, pump, drain, or overflow route. The worksheet deliberately asks the user to enter a target or capacity from a named source rather than embedding a universal rate. University extension descriptions show that NFT, deep-water culture, ebb-and-flow, and drip systems move or aerate solution differently; those descriptions do not make one flow or schedule correct for every crop and installation.
Use the result as a dated commissioning or inspection record. Identify the exact equipment and source for each target, measure representative outlets with consistent units and timing, calculate the scenario, observe a controlled operating test, and save the after-test measurement. Stop and obtain qualified help when leaks, electrical exposure, overflow, unexpected siphoning, blocked returns, pressure, structural loading, or food-safety consequences exceed routine arithmetic.
The target is multiplied by channel count; reserve is applied only to the requested pump comparison. Measured distribution uniformity is the lowest active channel divided by the average active channel, while zero-flow channels remain visibly flagged. All streams and capacities are converted to a common unit before totals are calculated. The model rejects negative or impossible entries and displays differences rather than silently changing the user's assumptions.
Core formulas
requested flow = target per channel × channel count
required with reserve = requested flow × (1 + reserve %)
measured DU = lowest active flow ÷ average active flow × 100
daily circulation = measured total × 60 × run hours
The chart is a comparison, not a safety grade. The table keeps component-level observations visible so a weak branch is not hidden inside a satisfactory total. Display rounding never changes the full-precision model.
Four channels with an entered 1 L/min target request 4 L/min before reserve. A 20% entered reserve makes the comparison flow 4.8 L/min. This is demonstration arithmetic, not a crop prescription, equipment approval, or acceptable-risk threshold.
Measured inlets of 1.0, 0.9, 1.1, and 0 L/min total 3.0 L/min; the closed branch remains an exception rather than disappearing from the average. This is demonstration arithmetic, not a crop prescription, equipment approval, or acceptable-risk threshold.
A pump may show positive flow at zero head but a negative installed margin at its real operating point, so the exact curve and a measured test belong in the record. This is demonstration arithmetic, not a crop prescription, equipment approval, or acceptable-risk threshold.
The worksheet is most useful when it accompanies physical measurements and a named operating procedure. Typical uses include:
It compares a source-entered target for each NFT channel with measured inlet flows, manifold and pump capacity, reserve, distribution uniformity, and circulated volume. It reports arithmetic from entered measurements rather than selecting a crop target or equipment specification. It does not prescribe NFT flow, slope, film depth, oxygenation, or crop suitability, and it does not approve the manifold, pump, drain, or overflow route.
No. Example values only make the interface usable on first load. Replace every target, curve point, loss allowance, runtime, reserve, and return fraction with a measurement or a traceable crop, system, manufacturer, or qualified-design source.
No. Catalogue ratings depend on the stated test condition. Water-pump flow changes with head and restriction; air output changes with backpressure, depth, tubing, manifolds, and diffusers. Measure the installed outlets and retain the exact performance curve and test conditions.
No. Airflow does not predict dissolved oxygen, and circulated water volume does not prove film depth, oxygen transfer, temperature, nutrient balance, sanitation, or crop suitability. Record calibrated dissolved-oxygen or other crop-specific measurements when a qualified plan requires them.
Reserve is an entered planning allowance, while blockage is a failure scenario. Neither proves that equipment, drainage, containment, controls, or alarms are adequate. Separating them prevents a favourable normal result from concealing a shutdown or obstruction exposure.
Measure actual flow at representative outlets, operate the system through start-up and shutdown under controlled supervision, inspect leaks and return paths, and compare observations with current manufacturer documentation. Have consequential plumbing, electrical, structural, and containment decisions reviewed by qualified professionals.
No. The worksheet cannot certify food safety, worker safety, crop health, electrical work near water, plumbing, waste discharge, or code compliance. Commercial operators must follow applicable authorities, documented sanitation programs, equipment instructions, and professional design requirements.