Fluval Flex 32.5 (123L)
Gear matched to this tank: lights by coral goal, skimmers and pumps checked against its rear chamber.
Best lights (by coral goal)
No seeded light fully covers this footprint at LPS / mixed intensity yet.
Compare all lights ranked for the Fluval Flex 32.5 (123L) →
Best protein skimmers (sized for medium bioload)
- rated to 75g, covers your 49g medium-bioload target (tank + margin)
- hangs on back — no chamber-fit constraint
- rated to 105g, covers your 49g medium-bioload target (tank + margin)
- hangs on back — no chamber-fit constraint
- rated to 66.1g, covers your 49g medium-bioload target (tank + margin)
- 4.33×3.54" footprint may not fit the ~4.125×3" chamber (community dims — verify)
- rated to 130g, covers your 49g medium-bioload target (tank + margin)
- 10.4×7" footprint may not fit the ~4.125×3" chamber (community dims — verify)
Compare all skimmers ranked for the Fluval Flex 32.5 (123L) →
Best return pumps (for ~5× display turnover)
- ~119 gph at the tank ≈ 4.4× display turnover
- 2.44×1.5" footprint fits the 4.125×3" rear chamber (community dims)
- ~158 gph at the tank ≈ 5.8× display turnover
- 3.4×1.88" footprint fits the 4.125×3" rear chamber (community dims)
- ~188 gph at the tank ≈ 7.0× display turnover
- 2.83×1.89" footprint fits the 4.125×3" rear chamber (community dims)
- DC pump — dial flow to taste
- 3.7×2.5" footprint fits the 4.125×3" rear chamber (community dims)
- strong: ~9.1× turnover — fine if controllable/throttled
Compare all return pumps ranked for the Fluval Flex 32.5 (123L) →
Tank specs
| Display volume | 27 gal |
| Total water volume | 32.5 gal |
| Outer dimensions (L×W×H) | 32.5 × 15.75 × 15.35 in |
| Rear chamber (W×D×H) | 4.125 × 3 × 8.5 in (community) |
| Stock return pump | 214 gph |
| Stock light | Integrated Aquasky 2.0 Bluetooth LED (~21W, 3000-25000K), FluvalSmart app |
Outer dims are the bounding box; curved front glass tapers usable depth at the corners. Display volume ~27 gal is an estimate (Fluval publishes only 32.5 gal / 123L total). Stock circulation pump ~214 GPH (810 L/h) at 120V. Chamber values from the inTank media basket (4-1/8 W x 3 D x 8-1/2 H); this model has two independent rear chambers, so D (~3 in) is a conservative per-chamber front-to-back constraint.