Documentation

Lighting Experiments

Mounting height, fixture position and the planned fixture comparison.

Outline

Purpose

To collect what has been tested about the light itself, covering position, height and eventually a second fixture, in one place, with the procedure used for each.

Background

The fixture over this tank is narrower than the tank is long, so coverage appears to be the limiting factor rather than peak output. The two are linked through mounting height: raising a fixture widens its footprint and costs intensity, so surplus output is what buys spread. That framing came from measurement rather than the spec sheet, and it decides which changes are worth testing. How the readings themselves are taken is not repeated here; that is set out in PAR Measurement Methodology.

Methodology

  1. Change one variable at a time: height, or position, or fixture, never two together.
  2. Re-measure the same positions with the same instrument after each change, following PAR Measurement Methodology.
  3. Compare against the previous survey rather than against a remembered impression.

Observations

  • Two tests have produced results so far: the position survey (Experiment 001), re-run on 8 August as the standing nineteen-position dataset, and the mounting-height test (Experiment 002), which found that raising the fixture reduced PAR at the ends. The survey is published with its raw readings; the height test is not, because those readings were never preserved as a standalone set, and it stays open until it is repeated.

Scope

  • Mounting height and its measured effect on end coverage
  • Front-to-back centring and distribution
  • The procedure used to compare two fixtures fairly

This page is an outline: the scope is settled and the measurements are being collected, but the full reference is unfinished.

Related equipment

ADA Solar RGBApogee MQ-510

Related experiments

PAR mapping across the planted layoutThe first PPFD survey of the planted layout, since superseded by the 8 August re-run.CompletedSolar RGB mounting height testRaising the fixture was tried, PAR at the ends decreased, and the fixture was returned to its original height. It stays open because the before-and-after readings were never kept as a dataset, so the result is a recollection rather than a record.In progressSolar RGB versus Solar RGB IIA like-for-like comparison of both fixtures on the same aquarium.Planned

References

Experiment 002 · Mounting height · Experiment 004 · Solar RGB II · PAR Measurement Methodology · ADA Solar RGB · ADA: Solar RGB published specifications · ADA Solar RGB II: retail listing and specifications