Best Reef Tank Equipment: Return Pumps, Wavemakers, Skimmers, Lights, RO/DI and Chillers

The return pump sets how fast water cycles through the sump: 3 to 5 times the system volume an hour is the usual target, and it can never exceed what your overflow drains. A 90 gallon reef with a 16 gallon sump wants about 320 to 400 GPH at the display.

Labels are at zero head. After 4 to 5 ft of pipe, elbows and a check valve, a DC pump delivers about 70% of the label, so a 1,450 GPH pump gives about 1,000 GPH, which is enough for a system up to about 250 gallons when dialed down. DC pumps turn down to match and have a feed mode.

Corals feed and shed waste in moving water. Aim for total in-tank flow, return plus powerheads, of about 10 to 20x the volume for soft corals, 20 to 30x for LPS and 30 to 50x for SPS. A 90 gallon LPS reef wants about 2,400 GPH in total; with a 320 GPH return, powerheads add about 2,000.

Use at least two on tanks of 4 ft and up, aimed so their flows meet and change direction. Random and pulse modes keep detritus moving without blasting corals in one spot.

Skimmer ratings assume a light fish load. Pick one rated at least 20% above your total system gallons, display plus sump, and more if you feed heavily. Check the skimmer's footprint and height against the sump chamber it goes in.

Soft corals do well at about 50 to 150 PAR, LPS at 100 to 200 and SPS at 250 to 400. Compact reef LEDs make a cone of light, so the question is how many it takes to cover the tank length at those levels. We plan one Prime 16 HD per 24 in of tank for soft and LPS, one per 18 in for SPS, and one Hydra 32 HD per 30 in or 24 in.

Run them on a ramped schedule of about 8 to 10 hours, usually at 60 to 80% of full power.

Every gallon of salt mix and top-off should start as 0 TDS RO/DI water. A 4-stage unit at the sink makes it for pennies a gallon, which matters when a 150 gallon reef takes 15 gallons a week in water changes plus evaporation.

Reefs stress above about 82 F. Lights and pumps run the water 2 to 4 F over room temperature, so a warm room in summer needs a chiller: about 1/10 HP to 40 gallons and 1/4 HP to 90, switched by the same controller as the heaters.

Calcium, alkalinity and magnesium are what growing corals use up; test them by titration weekly once corals are growing.