Tier 1 Metal Aquarium ★★

Taken all the way down to base materials, one Tier 1 Metal Aquarium is 3 crafting steps deep and needs 6 intermediates — Chromite Ingot ×3, Steel Plate ×2, Clear Glass Lens ×1 and 3 others — which resolve to 11 distinct raw materials totalling 53 units, plus 52 crystals.

That bill outweighs 12,925 of the 13,602 recipes tracked here and 1,371 of the 1,441 Armorer ones, and 337 recipes nest deeper.

Only 6 of those crystals go into the final step; the other 46 are burned by the intermediates, so the real crystal cost is 15 Fire Crystal, 9 Earth Cluster, 8 Fire Shard and 4 other kinds.

The chain crosses three disciplines — Armorer to Lv 70, Blacksmith to Lv 70 and Alchemist to Lv 28 — so no single class can finish it unaided.

10 of the 11 raw materials come out of the ground, and one of them is time-gated: Chromite Ore (10:00, 22:00). The widest gap between consecutive opening times is 12 Eorzean hours, about 35 real-world minutes.

Of the intermediates, Steel Ingot has the widest use: 125 recipes call for it, spanning seven of the eight crafting classes.