20 gallon reef tank setup with compatibility checks
A 20 gallon reef is a good first soft-coral target if the fish list stays modest and evaporation is controlled.
Small tanks need enough heat without an oversized stuck-on failure.
Target the 10-30x band: 200-600 GPH before placement tuning.
Use bioload headroom rather than the most optimistic number printed on the product page.
A typical 20g footprint needs coverage across about 24 x 18 in and the 50-150 PAR band.
Monthly supplies often land around $20-$35 before livestock and repairs.
The final answer depends on actual equipment, source water, livestock, and maintenance plan.
What this build has to get right
- Plan flow around coral comfort, not only maximum pump output.
- Use the heater band; small tanks can overheat quickly.
- Choose livestock that still fits at adult size.
Better than a generic shopping list
A 20 gallon plan can fail even when every product is individually good. ReefCrafter checks whether heater wattage, flow, light spread, nutrient export, budget tier, and livestock intent all agree before the cart becomes the build.