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Fishician®

Plan an aquarium build in the order the decisions actually depend on each other

Plan the animals, space and running costs before buying equipment. Each choice affects the next.

3 min readUpdated October 3, 2026

About this guide

Planning

By Fishician

Published September 12, 2026

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The short answer

  • Animals first. Adult size, water type, groups, temperament and diet set every later choice.
  • Then the room. Filled weight, floor, stand, power, light and access for maintenance.
  • Then the tank. Sized to the adult plan. Footprint usually matters more than gallons.
  • Then equipment. Chosen for the plan, with specs checked against the manufacturer.
  • Livestock last. Only after tests prove the biofilter works.
An empty glass aquarium on a sturdy cabinet with a tape measure nearby
Allow room for the tank, its support and maintenance access.
Buy in this order
  1. Tank and standNothing else can be tested without them
  2. Filter and flowChosen for biological capacity
  3. Heating and lightFor the species and the room
  4. Substrate and rockThey change volume and layout
  5. Water prep and testsConditioner, salt, test kit
  6. LivestockLast, after a proven cycle

Keep test supplies usable

Expired or poorly stored reagents can give inaccurate results. Check expiry dates and follow the kit’s storage instructions; budget for replacements.

Turn the idea into a build specification

This guide produces a shopping and verification sheet. It does not replace the first-aquarium decision or the water-testing startup protocol.

Tank and site
Inside dimensions, working water line, outside footprint, stand requirements, filled-system support, lid clearance and the route for bringing it into the room.
Stocking requirements
Species identity, adult group and space needs, water type, temperature needs, feeding access and any conflicts still to resolve.
Equipment evidence
Exact model and regional version, manufacturer manual link, dimensions, voltage, installation limits, replacement parts and questions unanswered by the retailer.
Water and maintenance
Source-water preparation, tests, buckets and siphon, waste-water route, service access and quarantine equipment.

Mark each line confirmed, needs measurement or needs manufacturer answer. A retailer's broad tank-size rating should not turn an unknown into a confirmed fit.

A hypothetical clearance check that prevents a wasted purchase

Illustrative dimensions, not a product recommendation: a cabinet has 40 cm of usable height. A candidate filter is 35 cm high, so it appears to fit. But its exact manual requires another 10 cm for hose connections or servicing. The required 45 cm exceeds the available 40 cm. Reject that combination or change the cabinet before ordering.

Record body dimensions and service clearance separately. Check hose bends, valve access and whether the unit can be removed without emptying the aquarium. Do the same for a lid that opens upward, a light mounting bracket and a heater's required submerged position. If the manual does not answer the question, ask the manufacturer rather than inventing clearance.

Separate purchase cost from running cost

Use your own current quotes, currency and electricity tariff. This worksheet has no live prices: tank and stand ___; filter ___; heating and light ___; lid/substrate/decor ___; water preparation and tests ___; quarantine and maintenance supplies ___; initial livestock ___; contingency ___.

Electricity calculation example: a hypothetical 10 W device running continuously uses 0.010 kW × 24 hours × 30 days = 7.2 kWh in that 30-day month. At an illustrative tariff of 0.30 currency units per kWh, that is 2.16. A thermostatic heater does not necessarily run continuously; calculate a scenario range or measure consumption rather than treating nameplate wattage as a monthly bill.

List recurring food, test reagents, conditioner, replacement parts and, for marine systems, salt and water purification. Put replacement intervals from the exact product instructions beside the cost. If recurring costs exceed your allowance, revise the design before buying animals.

Keep an acceptance record for the finished build

  1. Record the actual fill volume, including connected vessels where relevant. Keep display volume separate from whole-system volume.
  2. Check equipment installation and operation against each manual, and independently measure water temperature.
  3. Check that ordinary maintenance can be performed without unsafe lifting or dismantling unrelated equipment.
  4. Keep test results demonstrating completion of the fishless-cycle protocol beside the stocking plan.
  5. Record unresolved issues and postpone livestock until they are resolved. Keep receipts, model numbers and warranty information together.

A saved builder list organizes decisions; it does not certify animal suitability, structural support or product safety.

Sources

Each source is listed with the part of this guide it supports.