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The seedlings on the windowsill tell you everything before you read a word of advice: pale stems leaning hard toward the glass, leaves spaced too far apart, a tray of plants reaching for light that never quite arrives. A windowsill is not enough light for seedlings. The fix is a light you control, hung close and left on a timer.
For most seed starters, that light is the Barrina T5 4-pack: four 2-foot bars that sit a few inches above a tray and cover it evenly. The Spider Farmer SF1000 2-pack is the step up for a serious setup, and the SANSI 36-watt bulb is the pick when you only need one socket filled. One popular bulb does not make the cut, and the reason is a single number.
The four lights, side by side
| Light | What it is | Power | Best for |
|---|---|---|---|
| Barrina T5 4-pack | Four 2-ft LED bars | 40W total | Seed trays on a shelf |
| Spider Farmer SF1000 2-pack | Two dimmable panel lights | 100W per light | A serious setup |
| SANSI 36W bulb | One BR30 bulb, E26 base | 36W | A single tray or socket |
| GE BR30 2-pack | Two BR30 bulbs, E26 base | 9W per bulb | One houseplant — not seedlings |
Best overall: Barrina T5 4-pack
The Barrina wins because it matches the job exactly. A seed tray is long and flat, and four 2-foot bars laid across a shelf put even light on every cell instead of a bright spot in the middle and dim corners. The bars run at 5000K full spectrum, which is daylight-white light, and together they draw 40 watts — four bars at 10 watts each.
Setup is the other half of the win. The bars link together, up to 16 fixtures on one run, and each bar has its own on/off switch, so you can light one tray without lighting the whole shelf. They run cool enough to hang a few inches above the seedlings without scorching them, which is where the light needs to be — our guide to how high grow lights should hang works through the exact distance.
Pros: even light across a whole tray; links up to 16 fixtures; separate on/off switch per bar; cool-running, so it hangs close safely.
Cons: bars are built for shelves and trays, not for lighting a room; a 4-foot shelf needs the longer bars.
Barrina T5 Grow Lights, 2ft 40W, 4-pack
Four even bars that cover a seed tray properly, with a switch on every bar.
Best premium: Spider Farmer SF1000 2-pack
The Spider Farmer is a different kind of light for a different kind of setup. Each panel is a 100-watt light built around Samsung LM301H EVO diodes, rated at 3.14 µmol/J, and each light covers 3 by 3 feet for leafy growth and 2 by 2 feet at full bloom strength. It dims, so you can start seedlings gently and turn it up as they grow, and it carries a 5-year warranty.
Buy this one when the seed starting has outgrown a shelf. If you are running a tent or a dedicated grow space, or you plan to keep plants under lights well past the seedling stage, the panels earn their keep. For a single tray on a wire shelf, they are more light than the job needs, and the Barrina costs less for the same result.
Pros: strong, dimmable panels with a 5-year warranty; covers a real growing area; the 2-pack lights two shelves or one tent.
Cons: more light — and more money — than a single tray needs; needs a tent or a frame to hang from.
Spider Farmer SF1000, 2-pack
Two dimmable 100-watt panels for a serious setup, with a 5-year warranty.
Best single bulb: SANSI 36W grow light bulb
Sometimes the setup is one tray and one spare socket. The SANSI 36-watt BR30 screws into any standard E26 socket — a clamp lamp, a desk lamp, a pendant — and puts out 65.6 PPF, which is real growing light rather than a warm glow. It is rated for 25,000 hours and ETL listed, and it is listed as the equivalent of a 400-watt bulb while drawing just 36 watts.
One bulb covers one tray, hung close. That is the honest limit: if you add a second tray, you need a second bulb, and at that point the Barrina bars cost less per tray. But for a single tray, a few herbs, or a pepper plant overwintering in a sunny room, the SANSI is the simplest answer in this roundup.
Pros: screws into any standard socket; 65.6 PPF is genuine growing light; 25,000-hour life, ETL listed.
Cons: one bulb, one tray — a second tray needs a second bulb; no dimming.
SANSI 36W Grow Light Bulb, BR30
Real growing light from a single socket — the simplest fix for one tray.
Not recommended: GE BR30 2-pack
The GE BR30 2-pack looks like a bargain at about $22 for two bulbs, and for a single houseplant it is a fine light. For seedlings it is not. Each bulb puts out 16 PPF, which is far below what a seed tray needs at any height you can practically hang it — the SANSI bulb above it puts out four times as much light from one socket. A tray under these bulbs will stretch toward them exactly the way it stretches toward a window.
GE makes a stronger bulb in the same shape, the GE PAR38 at 32 watts and 50 PPF, and that one can do the job. The BR30 cannot, so skip it for seed starting and save it for the houseplant on the bookshelf.
What the winner is worse at
The Barrina bars light the tray directly beneath them and nothing else, which is exactly right for seed starting and useless for anything bigger. If your plan is a grow tent, a 4-by-4 space, or plants that will live under lights for months, the bars run out of reach and the Spider Farmer panels take over. The bars also assume you have a shelf to hang them from; a single tray on a table with no frame above it needs a stand or a different light. Buy the bars for trays, the panels for rooms, and the bulb for one socket.
Setting them up right
A good light hung too high still leaves seedlings stretching. Fluorescent and LED bars belong 2 to 4 inches above the seedlings, raised as the plants grow, and left on 14 to 16 hours a day on a timer — the full setup is in our guide to hanging grow lights. Pair the lights with a proper station — trays, heat, and airflow — and the seedlings stay short and sturdy instead of stretching. Our seed-starting station guide covers the rest of the build, and our start-seeds-indoors guide walks through sowing itself. Once the seedlings are ready, harden them off before they meet the garden.
Bottom line
Buy the Barrina T5 4-pack if you are starting seeds on a shelf, because four bars at a few inches cover a tray better than anything else at the price. Buy the Spider Farmer SF1000 2-pack if the setup is a tent or a dedicated space. The SANSI bulb is the pick if one tray and one socket is the whole job. Skip the GE BR30 for seedlings — 16 PPF is a houseplant light wearing a grow-light label. Hang whichever you buy close, put it on a timer, and the next tray will stand up straight.
