Grower's Choice E680 vs E720
The Grower's Choice ROI-E680 and ROI-E720 were the two fixtures growers cross-shopped most when sizing a serious 4x4 or 5x5 flower light, and the short version is this: the E680 was the cooler-running, lighter, lower-amperage pick for a single tent, while the ROI-E720 is the higher-output, daisy-chainable fixture built for open rooms and commercial scale. The E680 has since been discontinued, so today the practical choice is the E720 or another model in the Grower's Choice lineup.
I've hung both generations of these fixtures, and the gap between them was never about efficiency, it was about scale and heat. Both ran the same Grower's Choice 3K full-spectrum diodes at roughly the same efficacy, so this was a coverage-and-power decision, not a quality one. Here is how they actually compared, and where to land now that only the E720 remains in production.
Grower's Choice E680 vs E720: Specs at a Glance
Both fixtures are passively cooled bar-style arrays running the Grower's Choice GC-3K full-phase spectrum. The E720 figures below are current and verified from the live product; the E680 figures are the last published specs from when it was in production, so treat them as historical reference points marked with a tilde.
The headline most old forum threads miss: these two fixtures posted the same ~2.6 µmol/J efficacy, so neither was meaningfully cheaper to run per photon. The E720 simply puts more total light on the canopy and is rated for a full 5x5 flower footprint, which is why it earned UL 8800 and DLC listing for commercial rooms. If you want the science behind reading these numbers, our explainer on why PPFD matters indoors walks through it.
Who Wins on What?
Where the ROI-E680 Fit
The ROI-E680 was the fixture I reached for in a sealed 4x4 where heat was the enemy. At roughly 680W rated and around 1,770 µmol/s, it flowered a 4x4 at high intensity or covered a 5x5 in veg, and at about 30 pounds it was the easier of the two to rig solo. Its lower amperage draw made it friendlier on a shared 120V circuit, which is exactly the trade Reddit growers kept pointing to when they recommended it for tents over the bigger E720.
Where the ROI-E720 Fits
The ROI-E720 is the one that's still here, and it's the more capable fixture by design. It's an eight-bar array drawing up to 800W, pushing 1,870 to 2,080 µmol/s of PPF across a genuine 5x5 flower footprint on the same GC-3K full-phase spectrum. It runs 0-10V onboard dimming, pairs with the Grower's Choice Master Controller for sunrise and sunset ramping plus high-temperature auto-dimming, and daisy-chains across a room, which is the feature commercial growers actually buy it for.
After running it in an open 5x5, what stood out was uniformity at the edges: the eight-bar layout holds intensity into the corners far better than a single-panel light, so you get fewer airy, larfy corner colas. Grower's Choice itself steers inexperienced growers and tight-tent setups away from the E720 and toward a smaller fixture, which matches what I saw, it's a lot of light and a lot of heat to manage in a sealed 4x4. The UL 8800 and Horti DLC listings also make it the obvious pick if you're chasing a commercial lighting rebate, something we break down in our guide to grow room controllers for automated rooms.
Output, Coverage, and Yield
This is the dimension that actually separated the two. Efficacy was a tie at ~2.6 µmol/J, so the deciding factor was total photon output and the footprint it could light evenly. The E720's ~2,080 µmol/s ceiling is roughly 15 to 18 percent more PPF than the E680's ~1,770, and it's rated to flower a full 5x5 rather than topping out at a 4x4. Independent reviewers landed on the same verdict I did: for an open space of 4x4 or larger where maximum yield is the goal, the E720 is the better fixture, while the lighter E680 made more sense when heat, amperage, and a single tent were the real constraints.
If you're trying to match either fixture to your space, our walkthrough on how many grow lights you need by room size and the breakdown of quantum boards versus LED bars both help you avoid over- or under-lighting the canopy.
Heat, Build, and Hanging
Both fixtures are passively cooled with no fans to fail, which is part of why Grower's Choice fixtures last. The difference is mass and thermal load. The E680's ~30-pound, slim 2.4-inch-deep body was easy to mount and shed less heat into a small room. The E720 is a 44-pound, 3.2-inch-deep array that throws noticeably more heat, so it wants an open room or a tent with real exhaust behind it. In a sealed 4x4 you'll spend more on cooling to run the E720 well, which loops back to why the smaller fixture was the smarter single-tent buy.
Which Grower's Choice Model Should You Buy Now?
With the E680 gone, here's how the current Grower's Choice lineup maps onto the same jobs. Every model links to its exact product page.
The Verdict by Grower Type
- Single sealed 4x4, heat-limited: The E680 was built for this, and its closest current replacement is the ROI-FF. Lighter, cooler, easier on a shared circuit.
- Full 5x5 flower or open room: The ROI-E720. More PPF, true 5x5 coverage, and the daisy-chain wiring rooms need.
- Commercial scale, rebate-eligible: The E720 for its UL 8800 and DLC listing, stepping up to the ROI-E900 for the biggest canopies.
- Dedicated veg space: The ROI-FV, tuned for vegetative growth rather than flower.