120 gallonsSPS Dominantpremium tier

SPS reef tank build with compatibility checks

An SPS reef is not just a stronger light. It is a full stability stack: light, flow, chemistry, export, and patience.

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

  • Use multiple lights for coverage, not only headline PAR.
  • Plan strong random flow and enough pump control to tune it.
  • Delay sensitive sticks until the tank proves stable.

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.