Lighting

Chihiros WRGB II Pro 90

Specification

Manufacturer
Chihiros
Model
WRGB II Pro 90
Purchase year
2026
Category
Lighting
Status
In useread from live inventory
Measured with
Apogee MQ-510 underwater quantum sensor

Overview

The fixture now lighting the tank. It replaces the pendant the measurement work on this site was built around, and the comparison between the two is the open question.

Why I chose it

The standing PAR survey found the constraint on this tank was spread rather than output: no position read below its working range, and the highest reading was more than three times the lowest. A bar the length of the tank starts from a different distribution than a pendant narrower than the tank, which is the thing being tested.

What I've learned

  • Measured spread improved on the fixture it replaced: across the positions re-measured after the swap, the ratio between the highest and lowest reading narrowed.
  • Four channels give control over the look that the previous fixture did not have, but the channel mix is a visual decision rather than a growth one.
  • The onboard sunrise and sunset ramp moves in visible steps roughly once a minute rather than continuously.

Installation

Hung over the tank on the manufacturer's hanging kit, replacing the pendant on the 17th of September 2026.

Configuration

  • Suspended over the UNS 90P on the hanging kit
  • Channels: Red 86, Green 86, Blue 95, White 15
  • Photoperiod: ramp begins 9:00am, full output 9:30am, ramp down begins 3:30pm, off 4:00pm
  • Set and scheduled from the manufacturer's app rather than from the controller

Maintenance

  • Wipe the lens when condensation or salt creep appears.

Known limitations

  • The onboard ramp steps rather than fading smoothly, which is visible at the start and end of the photoperiod.
  • Nothing reads the fixture's state back: what it is set to is known only from what was last entered in the app.
  • No manufacturer PAR data is published for it, so every figure on this site for this fixture is measured here.

Current observations

  • Running Red 86, Green 86, Blue 95, White 15. The intent behind that mix is to approximate the clean, cool, saturated appearance of the fixture it replaced rather than a magenta or a warm one. These are channel percentages on a four-channel fixture and they do not convert to a colour temperature: the previous fixture looks cool, but Kelvin is not a reliable conversion between RGB aquarium fixtures.
  • PAR after the 18th of September replant: Rotala 'Blood Red' approximately 80 µmol/m²/s at the newly replanted tops, Rotala 'Orange Juice' approximately 115, and the front-centre red group approximately 100.
  • The Blood Red figure is taken at freshly replanted tops and will rise as the stems grow toward the light, so it describes the stems' current height rather than a fixed value for that position.

What this item is doing now, as distinct from what has been learned over time.

Live measurements

Positions measured
14
Measured range
70–175 µmol/m²/s

Read from this device on the overview page.

Maintenance history

Installed
Sep 17, 2026

Related experiments

No experiments reference this item yet.

Related documentation

Would I buy it again?

Undecided.

Too early. The spread it was bought for did improve on measurement, but the comparison against the fixture it replaced is not finished, and the fixture it replaced is still here.

Future upgrade considerations

  • Whether the channel mix settles where it is or moves further toward the appearance of the fixture it replaced.
  • Whether intensity rises from here, which is a question about what the tank can absorb without feeding algae rather than about what the fixture can produce.