LED grow lights - is "bar" style or "quantum board" style better for growing weed?

[MeowMeow]

Sorry for asking multiple questions in one day. I was just wondering what you all thought about a few things.

So far I've only ever used the "quantum board" style (pictured) where all the lights are spread out on a panel. But lately I've been seeing more growers using LEDs with the diodes on bars ("bar" style - also pictured). Some people say the bar style ones are easier to cool, but others say that wattage is what matters more for heat. But I have a rectangle 2x4 grow tent and I'm not sure I've seen any bar style LEDs that would fit it anyway.

Is one type better than the other as far as heat or results? Or does it just depend on the particular model/brand? Or is it more about finding the right one for your space.

Any thoughts about LEDs at all are highly appreciated!

[Rootsruler]

I think that heat generation depends on the manufacturers design so each is different in their heat output.

For me, the difference between bar and quantum is in hot spot elimination and light spread. The quantums usually have a hot spot and the light energy dissipates the farther out to the light edge you go. With bar lights you should have pretty much even coverage across the width and length of the light.

I like to ScrOG so bar lights are better suited for my style of grow where I want even coverage out to the edge of the tent. That's not to say that quantums aren't effective. I've had many successful grows with quantum lights but if you are in the market for a new light or your old one gave out I would probably opt for a bar light.

My last grow with quantums. If I find a good deal on a bar light I might pick one up but with all the BS about tariffs now may not be the best time to be trying to buy one.

[MeowMeow]

Your plants look incredible! 😍

[Rootsruler]

Thanks. Most of the work was done by the plants. I just kept watering and watching the grass grow!! Hahaha!

[Bluey]

Bar almost always unless up front cost is the limiting factor

https://www.spider-farmer.com/products/spider-farmer-g4500-cost-effective-full-spectrum-led-grow-light/

https://www.spider-farmer.com/products/se4500-430w-led-grow-light/

https://www.mars-hydro.com/smart-fc4000-samsung-lm301h-evo-led-grow-light

The above lights will be perfect for vegging and flowering in a 4x2.

I only veg or start clones in a 4x2 so a slightly cheaper quantum board is fine for my needs. If your only growing autos and on a 18/6 schedule a lower wattage light will work fine for you also but you will get better results with a bar style lights when in flower given the more even light spread and larger sweet spot.

[MeowMeow]

Thanks for sharing your experience, I appreciate it! Spider Farmer and Mars Hydro seem like some of the best from what I've seen in grow journals online.

[Bluey]

They are mass produced budget lights that work really well.

You can basically buy them direct from the manufacturers, which I recommend.

There are lights costing double and triple the above. Do they produce better quality buds? No. Do they produce higher yields? No. Do they last longer? Maybe, but not two to three times longer. Do they have better after sales service? Yes, but only if you need it which typically means you have a problem with their product or you are not sure what you're doing.

Are they worth the difference? Not for me to say

[MeowMeow]

Yeah, sometimes paying more doesn't necessarily mean better!

[Rootsruler]

Take a look at ViparSpectra. I won one of their XS1500Pro lights in a site raffle. I wasn't expecting much as it was a small 150w light.

Boy was I wrong. Although the chassis looks like a quantum board setup it performs very much like a bar light due to improved lensing and some other tweeks they did. I took light measurements using my Tent Buddy app and the numbers were pretty consistent from center to edge. I would classify it as the best all around 2 x 2 light currently.

The only drawback to the light is the dimmer. It's a step dimmer and not a rotary dimmer so you can't fine tune the light solely from the dimmer. You'll have to find the closest setting and adjust your light height to arrive at the PPFD you want at that time. Not a big deal but kind of annoying when you're used to adjusting light output from the dimmer.

[Rootsruler]

Something you may want to keep in mind. Buying one light to cover your tent needs is fine but it may be better to buy 2 smaller lights that total up to the wattage you want in the tent. In your case, your 4 x 2 would work perfectly with 2 of the XS1500Pro's I noted earlier. If one of them dies you still have lighting to keep your plants going until you get your replacement light. Probably a fairly rare case but when it does happen you'll be glad you did it that way. The 2 light setup is probably slightly less efficient energy wise than one larger one but having the luxury of a backup can be a lifesaver.

[Bluey]

Two quantum lights is a good idea rather than one quantum light but Id still go bar light if even spread was the goal
.

Yes a 1200w bar light is a lot but it works well with my sf7000 and an sf2000 in the flower room.

The bar light is far superior to the quantums for results and easier to grow under.

[MeowMeow]

Bluey It's cool to hear from someone who's tried both quantum boards and bar lights, and found the bar lights to be better. Thanks!

[golfnrl]

Be sure to check out Migro on youtube or the web site.

[Rootsruler]

Fo' Sho"! Great info at the Migro youtube channel.