Last Updated: September 30, 2026
PAR questions usually get answered with a fixture’s peak number, which is the wrong figure to plan around. What matters is the PAR measured where a coral actually sits. Figuring out what par do you need from reef led light starts with your corals’ reference range, then confirming the reading at their exact placement.
As an Amazon Associate we earn from qualifying purchases.
By David Nguyen
Quick answer: For most people in 2026, the best what par do you need from reef led light is the Soft corals — our #1 rated choice. See the full ranked comparison, alternatives and buying advice below.
How Much PAR a Reef Tank Actually Needs
The short answer: use a coral-type reference range as a starting frame, then measure at the coral. Soft corals plan lower, SPS higher, but the guides disagree on exact bands, so the table below gives ranges as planning tools rather than hard minimums you should lock in before ever reading your own water.
| Coral Group | Reference PAR Range | How to Read It | Exception |
|---|---|---|---|
| Soft corals | ~75-150 PAR | Planning range; confirm at coral | Species and placement shift it |
| LPS corals | ~150-250 PAR (one guide) | Another guide groups soft/LPS 75-150 | Acclimate before higher PAR |
| SPS corals | ~250-350+ PAR (one guide) | Another guide uses ~200-350 | Depth and flow change tolerance |
| Measured spot | Reading at coral location | Peak or surface PAR is not this | Meter placement decides the value |
Quick Answer by Coral Type
Match the target to what you keep. Softies plan around 75-150 PAR, LPS around 150-250 in one common guide, and SPS around 250-350 or more, though the numbers shift between references. These are starting frames for choosing and dialing a fixture, not thresholds a coral will fail to survive just below.
Placement and acclimation move the target as much as species does. A new frag wants less than an established colony, and a coral high on the rock sees more than one on the sand, so pick a range for your corals and their spot, then treat it as a plan to verify rather than a fixed rule.
Why PAR Ranges Are Not Universal
Published ranges disagree because they come from different educational sources. One Bulk Reef Supply guide separates soft, LPS, and SPS into distinct bands, while another groups soft and LPS together at 75-150 PAR and uses roughly 200-350 for SPS, so no single chart is the definitive requirement for every reef.
Because of that spread, writing a hard minimum from any one band is a mistake. Use the overlap to set a conservative target and then confirm with a meter, since your species mix, acclimation history, and depth matter more than which chart you happened to read when you planned the tank in the first place.
Measure PAR Where the Coral Lives
The only number that truly applies is a reading at the coral’s placement, not at the surface or under the fixture’s brightest point. Peak figures overstate what reaches a coral on the sand, so a meter held at the actual spot converts a fixture’s spec into the value your coral is really receiving.
Take readings at several placements, since one tank has many light levels. High rock, mid-rock, and sand can differ sharply under the same light, which is exactly why placement is a tool: you can move a coral to its target range rather than changing the whole fixture whenever a reading comes back off.
How to Read Manufacturer PAR Maps
Read a map with its full test conditions in hand. The ReefLED G2 60 shows 500 PAR at the surface and 100 PAR at 20 inches in a 20-inch cube with a 7-inch mount, an 80% drop between those two points that is specific to that one test rather than a formula you can apply to every tank.
Do not interpolate an unpublished curve or infer PAR from wattage, since neither reflects your setup. The G2 115 shows 500 to 150 PAR at 20 inches in a larger cube, a 70% fall, which proves how much geometry changes the numbers, so use each map as a shape and verify the real values yourself.
Adjust for Your Situation
The reference ranges get you close, but your corals, depth, and fixture behavior fine-tune the real target. Use the adjustments below to move from a planning number to a working one, since two tanks with the same corals can need different settings once depth, placement, and acclimation history are taken into account.
Adjust for Coral Type and Placement
Within a tank, place corals to their range rather than forcing one intensity everywhere. A softie at 75-150 PAR and an LPS reaching toward 200 can share a system if you use the light gradient, seating each where the meter reads its target instead of setting the fixture for one coral and stressing the rest.
Remember the bands overlap, so a mixed softie-and-LPS tank often lives comfortably in the 75-150 zone with a few brighter spots. Let the meter and the coral’s response guide placement, and re-check after a rescape, since moving rock changes the light map even when the fixture setting has not changed at all.
Adjust for Tank Depth
Depth is the biggest single variable, because PAR falls sharply with distance from the light. Red Sea’s own data shows the G2 60 dropping about 80% from surface to 20 inches, and the deeper G2 170 reads 550 PAR at the surface down to 130 at 32 inches, so a tall tank needs more attention to falloff.
Those falloff figures belong to their specific tests, so treat them as patterns, not formulas. In a deep tank, plan for lower PAR at the sand and either raise light-hungry corals or choose a fixture with output to spare, then confirm the bottom readings with a meter rather than assuming the surface number carries down.
Adjust With Dimming and Acclimation
The right PAR today is not the right PAR for a brand-new frag. Corals need to acclimate to intensity over weeks, so a controllable fixture lets you start well below target and ramp up, which protects color and tissue far better than dropping a coral straight into its final reference range on day one.
Use the app or dial to step intensity, watching the coral rather than the clock. If a piece pales or browns, ease back before pushing higher, since the goal is the coral settling into its range comfortably, not hitting a chart number on a fixed schedule that ignores how the animal is responding.
Adjust for Fixture Map Limits
Manufacturer maps have edges, literally and figuratively. The Hydra Edge 44HD publishes 60-125 PAR across 24 inches at a stated height, which is not measured the same way as Red Sea’s underwater data, so you cannot mix the two or assume the map’s numbers hold outside its tested span and mounting height.
Treat a map as valid inside its conditions and unknown outside them. Where your tank differs in depth, width, or mount height, the published values drift, so a meter reading at your corals is the correction, turning a fixture’s tested map into the actual PAR your specific reef receives under your own setup.
Frequently Asked Questions
These questions come up once the ranges are clear but the tank is real. Each answer leads with the direct call, then the condition that shifts it, so you can turn a reference band into a working target for your own corals, depth, and acclimation stage rather than treating a chart number as final.
Is There a Single PAR Number for a Reef Tank?
No, because it depends on the corals and their placement. Softies plan near 75-150 PAR, SPS near 250-350 or more, and the guides even disagree on the exact bands, so a single universal number would be wrong for most tanks. Choose a range for your species and verify it at the coral.
Placement and acclimation then fine-tune it further. A new frag wants less than an established colony, and depth changes what arrives, so the useful answer is a target range you dim into and confirm with a meter, not one figure you can quote for every reef regardless of what it holds.
Can I Estimate PAR From the Fixture’s Wattage?
No, wattage does not predict PAR at the coral. Two lights of similar power can deliver very different intensity depending on optics, mounting height, and depth, so inferring PAR from watts skips every variable that actually decides the reading. Use published maps under their conditions, then measure in your own water.
The same applies to interpolating an unpublished curve between two points. Red Sea’s maps show falloff specific to each cube size, so guessing values between them for your own tank imports error. A meter at the coral is the only reliable way to convert a fixture into the PAR your reef truly gets.
Does Peak PAR Tell Me What My Coral Receives?
No, peak PAR describes the brightest point under the light, usually near the surface and center, not where most corals sit. A coral on the sand or off to the side receives far less, so planning placement around a peak figure leaves lower and edge corals underlit despite an impressive headline number.
Read the falloff instead. A fixture that peaks high still drops steeply with depth, as the G2 60’s roughly 80% fall to 20 inches shows, so the value that actually matters is the reading at the coral’s exact spot, which a meter gives you and a peak number on a spec sheet never can.
How Do I Turn a Reference Range Into My Target?
Start with the band for your corals, pick a conservative point within it, and then confirm with a meter at the placement you have in mind. If the reading is high, move the coral lower or dim the fixture; if low, raise it, so the range becomes a real target rather than an abstract one.
Then let acclimation set the pace. Begin below the target for new frags and ramp over weeks, watching color and expansion, so the coral settles into its range comfortably. The chart gives the frame, the meter gives the truth, and the coral’s response gives the final word on where the number should land.
Final Thoughts
Treat published ranges as a starting frame, not a rule, and let a meter at the coral turn them into a number you can trust. The honest answer to what par do you need from reef led light is whatever your specific corals read at their placement after acclimation, so plan with the bands and verify at the coral.
Ready to decide? Our #1 pick for 2026 is the Soft corals.
Live price & availability on Amazon.
Related Reviews & Guides
Nano Reef Tank Setup: How It Works and What to Watch For
Aquarium Salt Marine Mix Reef Review
