Field Notes

Field Notes

The measurements, experiments and technical references behind the journey. The journal tells what happened. These pages show how it was measured.

Featured investigation

Measuring PAR Distribution Across a 90P Using the Original ADA Solar RGB

Twenty underwater readings across a 90 cm tank under a single fixture, with the complete method, the raw data as stored, the mounting-height test that failed, and an explicit account of what the numbers do not establish.

I expected a weak light. I measured an uneven one.
50–176measured rangeµmol·m⁻²·s⁻¹
20positions
3.5×highest ÷ lowest
The labelled tank photograph
Each species labelled at its position. Every PAR figure on this site was taken underwater at one of these spots.

Read the complete survey

Experiments5

Including the ones whose result contradicted the expectation, which are the ones usually left out.

PAR mapping across the planted layoutTwenty underwater PPFD measurements mapped against the planted layout.CompletedSolar RGB mounting height testRaising the fixture was tried, PAR at the ends decreased, and the fixture was returned to its original height.In progressAquasoil ammonia declineAmmonia tracked from setup through to consecutive zero readings.In progressSolar RGB versus Solar RGB IIA like-for-like comparison of both fixtures on the same aquarium.PlannedCanopy versus substrate PARMeasuring the same positions at substrate and at canopy height as stems fill in.Planned

The experiment archive

Methods3

How a reading is taken here, and what it is allowed to claim afterwards.

PAR Measurement MethodologyHow PAR is measured on this tank, and what the numbers do and do not mean.PublishedMeasurement PhilosophyWhy this project measures rather than guesses, why PAR is only one variable, and why unfavorable results are published.PublishedExperimental MethodologyThe standing procedure for experiments on this aquarium: control of variables, calibration, measurement, comparison, and how conclusions and limitations are written.Published

Plant observations

Every species in the layout with the light measured at its own position, against the working range it is usually kept in — not a figure quoted for the tank as a whole.

The plant index · The current plant map

Equipment observations12

What long-term use has actually shown, kept separate from what the manufacturer claims.

ADA Solar RGBReliable across approximately six years of daily use with no failures.→Apogee MQ-510Underwater readings differ enough from above-water assumptions that only in-water measurement is used on this project.→EHEIM Professionel 5e 700Flow scheduling is genuinely useful: a lower night profile is set independently of the day rate.→CO2 Regulator + SolenoidBecause carbonate hardness is kept at or near zero, the pH/KH table is not usable here, so CO₂ is inferred from the pH drop off the morning degassed baseline instead.→Neptune ApexKeeping safety limits on the controller rather than in the automation layer has proved to be the right split, because the tank keeps running when the software is restarted or broken.→Milwaukee MA911B/2 pH probeBecause CO₂ is controlled from a pH drop rather than an absolute value, probe drift matters less than probe stability over a single day.→

The equipment index

Raw records and reference7

CO₂ AutomationCO₂ automated on a fixed window with hardware safety limits, why the usual pH/KH table does not apply here, and why the pH loop is deliberately left open.PublishedLighting ExperimentsMounting height, fixture position and the planned fixture comparison.OutlineAquasoil CyclingAmmonia release from fresh aquasoil and the water-change schedule that follows it.PublishedPlant ProfilesPer-species notes: measured light at that position, growth habit, and observed color.PlannedEquipment NotesWhy each product was chosen and what has been observed using it.PublishedExperiment ArchiveEvery experiment, including the ones whose result contradicted the expectation.PublishedFuture EvaluationsHow an independent evaluation is run, and what a manufacturer can expect.Planned

All documentation · What is queued next