Pre-built stocking plan

20-gallon Nano Reef Stocking Blueprint

Complete 20-gallon AIO nano reef stocking blueprint with timeline.

Setup

20-gallon AIO (Waterbox AIO 20, Innovative Marine Fusion Pro 20, Red Sea Reefer 170)

Fish stocking

Pair Ocellaris clowns
1x Yellow watchman goby + tiger pistol shrimp pair
1x Royal gramma OR firefish

Invertebrates

15x mixed CUC (turbo, trochus, nassarius, hermits)
1x cleaner shrimp
5x sexy shrimp

Coral progression

Mushrooms (multiple species)
Zoanthids (multiple morphs)
GSP, Kenya tree, leather coral
LPS month 4+: torch, hammer, frogspawn, acan

Stocking timeline

Week/Phase 1Cycle 4-6 weeks

Week/Phase 2CUC week 5

Week/Phase 3Clown pair week 6

Week/Phase 4Goby + pistol month 2

Week/Phase 5Soft coral month 3

Week/Phase 6LPS month 4-6

Week/Phase 7SPS only after 6+ months stable

Tools for this build

Use the stocking calculator to verify, the water change calc for ongoing maintenance, and the maintenance schedule generator for printable weekly tasks.

More blueprints

Browse the full blueprint library for other tank sizes + types.

Aquarium-keeping fundamentals

Whatever specific topic brought you here, four fundamentals govern long-term aquarium success: water quality, parameter stability, biological filtration, and species-appropriate husbandry. Skip any one and the others struggle to compensate.

Water quality: ammonia + nitrite at zero, nitrate under 30 ppm freshwater + 10 ppm reef. Test weekly with API or Salifert kits. Use our water parameter checker to score your readings against your tank type.

Parameter stability: stable wrong parameters beat fluctuating ideal parameters. Most fish tolerate a wide pH range if it's stable. Sudden swings of 0.4+ pH or 5+°F kill fish faster than chronic suboptimal values. Use temperature controllers (Inkbird) + automated dosing for consistency.

Biological filtration: the bacterial colony on your filter media + rock + substrate is the engine. Never replace all media at once. Use our filter turnover calculator to size correctly.

Species-appropriate husbandry: research adult size, territoriality, diet, and tankmate compatibility before purchase. Use our tank stocking calculator + compatibility guides.

Frequently asked questions

How long does an aquarium take to set up? 4-6 weeks for full cycling + first stocking. Use our cycle ETA calculator + how long does cycling take.

What's the best aquarium for beginners? 20-gallon long. Big enough for parameter stability, small enough for budget + space. See beginner picks.

How often should I do water changes? 25-30% weekly. See water change frequency Q&A + water change calculator.

Why does my fish keep dying? 5 leading causes: uncycled tank, wrong species pairings, no quarantine, undersized tank, neglected water-change schedule. See full diagnosis.