120 gallonsSPS Dominantpremium tier

Premium reef tank build with compatibility checks

Premium gear only matters when it buys stability, redundancy, usable control, or a cleaner path to demanding livestock.

Heater band
300-600 W

Split heat around two 150 W heaters when possible.

Display flow
6,000 GPH

Target the 40-60x band: 4,800-7,200 GPH before placement tuning.

Skimmer headroom
300 gal rating

Use bioload headroom rather than the most optimistic number printed on the product page.

Lighting coverage
1,440 sq in

A typical 120g footprint needs coverage across about 60 x 24 in and the 250-350 PAR band.

Startup budget
$9,700-$15,400

Monthly supplies often land around $145-$280 before livestock and repairs.

Planner handoff
Full check

The final answer depends on actual equipment, source water, livestock, and maintenance plan.

What this build has to get right

  • Do not let premium equipment hide weak fundamentals.
  • Buy redundancy where failure kills livestock.
  • Check light and flow coverage as a system, not as individual product flexing.

Better than a generic shopping list

A 120 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.