Research — LM301B vs LM301H for Cannabis (April 2026)

Source: research subagent query, 2026-04-11. Captured verbatim below so future iterations of this project don't have to re-run the search.

Samsung LM301B/H/H EVO for Commercial Cannabis — April 2026

1. LM301B vs LM301H vs LM301H EVO — the real differences

Key truth: the original LM301B and LM301H are nearly identical in µmol/J. The H's advantage is package chemistry (better sulfur/moisture resistance and marginally better thermal path), which matters in humid flower rooms long-term. The EVO is the one with a real efficacy jump — Samsung redesigned the phosphor stack around 2022 and claims ~2880 PPF/W at 65 mA (roughly 8–12 % more photons per watt than the B/H).

At high drive currents (350 mA+, which is what commercial boards actually run at), all three drop to ~2.5–2.7 µmol/J at the diode. Driving them soft is the whole game.

2. AliExpress "LM301H" — real or clone?

Mostly clones or B-bin rejects. Real tells:

• Genuine Samsung diodes have laser-etched Samsung logo visible under magnification; clones have printed or blank tops.
• Reputable board builders (HLG, Kingbrite in its genuine line, Meijiu) publish Samsung batch/reel photos. If the vendor can't, assume clone.
• Price floor: a genuine LM301H 480 W-equivalent board (~1 200 diodes) can't realistically sell under ~$140–180 at retail. Anything at $70–90 is either clones, LM281B+ (a cheaper Samsung mid-power chip often relabeled), or San'an / Hongli Chinese equivalents.

Typical markup: genuine board runs 1.8–2.5 × the clone price. Kingbrite is the gray-zone vendor most DIYers on Rollitup/Reddit r/HandyLights trust — they do sell real Samsung but you have to specifically order the "genuine" SKU and pay for it.

3. Best spectrum recipe for flower, commercial, 2026

Current practitioner consensus (HLG, Migro, Shenzhen ODM builders, and the r/HandyLights / Rollitup DIY LED threads):

• 85–88 % Samsung LM301H EVO or LM301H at 3000K or 3500K (3500K is edging out 3000K for flower because the extra blue holds structure and reduces stretch)
• 10–12 % deep red 660 nm — Osram Oslon SSL 150 or GH CSSRM2.14 (the Osram 660 nm is still the benchmark; Epistar 660 nm is the budget option and is noticeably less efficient)
• 1–2 % far-red 730 nm — optional, mostly for end-of-day Emerson effect triggers rather than continuous use
• 0.5–1 % 395–405 nm UV-A — Seoul Viosys or Nichia; NOT UV-B (UV-B is a separate supplemental bar, never mixed into main board)

The "pure white + 660 nm" school (Bruce Bugbee's lab position) argues far-red and UV add cost without yield. The practitioner school (Rollitup/icmag veterans) swears by small far-red and UV doses for trichome density. Both are defensible; commercial growers optimizing $/gram tend to skip far-red and UV and just run white + 660 nm.

4. Competitors in April 2026

• LM301H EVO is the current efficacy king among mid-power white LEDs. Benchmark.
• Bridgelux Thrive / EB Gen3 — very close, sometimes cheaper, spectrum tuned for hort (built-in phosphor red boost). Used by a lot of Chinese OEM boards.
• Seoul SunLike — beautiful full spectrum, terrible efficacy (~2.5 µmol/J). Niche/marketing only.
• Luminus SST-20 — high CRI, single-emitter, not competitive as a flower workhorse.
• San'an / Hongli / MingBon (China) — closing the gap fast, 5–10 % behind Samsung on efficacy, 40–50 % cheaper. Quality variance is the issue.

Short answer: LM301H EVO is still the benchmark in April 2026. No Samsung successor has been announced in training data.

5. Realistic fixture-level efficacy

Wall-plug µmol/J for a well-built HLG-style board + Meanwell HLG-series driver in 2026:

• Marketing claims: 2.9–3.1 µmol/J
• Independent testing (Migro YouTube, Growmau5 teardowns, HLG Photon test reports): 2.6–2.8 µmol/J at the wall is honest for an LM301H EVO build. 2.9+ requires soft-driving (running 600 W of diodes at 480 W), which is how manufacturers get headline numbers.
• 3.0+ µmol/J claims are either test-condition cherry-picks or outright lies. Treat skeptically.

Fluence SPYDR 2p tested ~2.7 µmol/J; Gavita 1700e ~2.6; Mars Hydro FC-E8000 claimed 2.85, independently tested ~2.6.

6. DIY vs commercial for "800 W top light" equivalent

Target: ~800 W draw, ~2 100–2 200 µmol/s output, 4×4 ft coverage.

DIY saves 50–70 % vs Fluence/Gavita, 30–45 % vs Mars/Spider Farmer. For 12 fixtures in one flower room the delta is meaningful: roughly $4.5 k DIY vs $8–10 k Mars Hydro vs $17 k+ Fluence. Tradeoff is no warranty, you eat failures, and insurance/compliance in licensed facilities often requires UL/DLC-listed fixtures — DIY boards usually aren't DLC listed, which can kill utility rebates (often $200–400/fixture in US commercial markets).

Practical recommendation for a commercial room: Mars Hydro FC-E or Spider Farmer G-series hits the sweet spot of DLC-listed, warrantied, rebate-eligible, and 80 % of Fluence performance at 50 % of the price. Pure DIY only makes sense if you're unlicensed/personal or the rebate math doesn't apply.

Sources leaned on: Samsung LM301H EVO datasheet (public), Migro LED testing channel, Growmau5 teardowns, HLG published test data, Rollitup and r/HandyLights DIY build threads, icmag LED subforum, Bruce Bugbee (Utah State) spectrum research. Dollar figures calibrated from 2024–2025 trends; verify with current Kingbrite/HLG quotes before committing to a 12-fixture order.