Building out a new room, need advice

Dbrn is the man for that

I thought I was clear. If you look at watts/dollar or ppf/dollar, the Mars lights (currently) look really good. The TS 1000 just doesn’t cover much more than 4sqft. Also, Mars seems to frequently change components without model number revision, and their prices have been volatile since COVID started.

Im gonna return the mars…ill find somethi g more appropriate for seedling stage and clones…but the more i read and read and read lol, the more im leaning to the hlg 550 vspec

1 Like

The 550, like all the HLG lights, is a good (efficient) and powerful light. There are shortcomings you should be aware of. With only one light, if you have a light failure you’re scrambling to find a replacement just to preserve your light cycle. If you want to run multiple grows, you’re buying more fixtures. Most importantly, small, single PCB-style lights don’t cover as evenly as arrays (either large single lights or multiple PCB lights).

Edit: I always come back to the same question: How much dried flower do you need per week/month/year? On a budget, I would always let that determine my other decisions. That light will make 20 ounces (and often more) every 3 months.

1 Like

There’s probably at least 50 members here growing with r-spec boards. The hlg 550 is good for flowering up to a 4x4. Doesn’t matter how many plants you have in that size space, the ppfd average won’t change with different plant count.


I don’t think I need or want that much (20oz) but I do really enjoy the growing portion. For reference I like hot peppers…but the hottest I like is maybe a jalapeño…that said I have a garden outside with 3 Carolina reapers, 8 scorpion peppers, 1 ghost peppers, 6 Japanese ornamental peppers, 2 pink ladies and 1 black pearl and no jalapeños… I grow those because I just enjoy growing things…I give almost all the peppers away to friends and locals who love hot pepper paste…and I think I could be going down a similar road…I want to grow for the fun of it, and because now I can…abut has always been something I’ve wanted to do but my job has prevented me from even thinking about it…we’ll I’m retiring in Aug next year, so I’m planning on going big and with a bang!! Lol.

As a scuba diver instructor, I am a firm believer in redundancy…so your point of the failure and scramble to save the grow makes me wonder…what In your professional gardening opinion would you suggest I do, build a light running 2 different drivers or 2 separate lights boards/strips?

1 Like

Instead of a single HLG 550 R Spec covering 4’x4’, you can use two HLG 260 XL RSpec fixtures, which each cover 2’x4’. They should actually cover a 4x4 better than the 550, and I’m happy to elaborate as to why if you’re curious.

1 Like

When you say they will do a 4x4 better, is that each or combined they would do better?

That was gonna be my suggestion also… And I have 2 HLG 600h V2 R spec… And I think I would be better off with 4 of the 260s instead, The cost isn’t all that much different… And there is a lot of benefits to having your lights split up…
I believe @KeystoneCops is saying combined.

1 Like

So could i run 3 of the 260s to cover the 2.5 x 5.5 space? Or would 2 be just fine? I found a calculator somewhere last night that suggested at least 800watts to cover a 3x6…so if i ran 3, then i would be around 780 (close enough i spose),

Also, can you daisey chain those lights all to run off one timer?

I don’t know your situation I would start with two and do a grow and go from there if it was me… I went all in on mine when I started and in hindsight I would rather have four of those lights now instead of the two big ones I have… But as far as coverage I think three of the wider ones would be more than ample…

Can you explain a little about how the 2-260s would be better than 1 550?

Im kind of a spreadsheet compare kinda guy, so i came up with a very quick chrt to show prices, and ultimately the cost over a basic grow

Light strength drops by a factor of 4 every time distance is doubled. For example, if a light makes photosynthetic radiation at a level of 1000 at 2 feet of distance to the canopy (that’s a random number, just for example) moving that light to 4’ from the plants reduces that power to 250. Same energy in. Same waste heat out. 1/4 the light to the plant.

My opinion is that you want to give the plant as much light as it can take for as little energy as possible, so the closer the light source is to the canopy the better. With most fixtures we still need a sizable distance between the light and the canopy because the light would simultaneously be too close to the center and too far from the edge of the plant.

Picture three styles of electric light:

A 1000w HPS bulb, no reflector

A single quantum board like the 650

And a strip-style array like the Fluence Spydr 2i

Imagine they all cover the same size flowering canopy at 5’ x 5’

The HPS is a single point source light. If you hung it 24” from the canopy dead center in the middle of the tent, it would be much closer to the flowers directly under it (24”) than the flowers at the edge (38”). Yes, there would be reflection off the walls, but direct light is better.

Imagine the QB 650. It has a lot of tiny LED chips. Probably hundreds of point sources of light. The board is still only 30” x 22”, which means it has a better spread than the HPS, but it will still be much closer to the buds directly under it than the buds at the edge of the tent.

Because of a principle called the Inverse Square Law, distance diminishes light strength dramatically. In order to have a very even coverage, the first two designs raise the lights up so that the relative disparity between the closest and furthest part of the canopy is closer.

The strip style PCB lights like the SPYDR line splay their boards and chips out over a much bigger area. That means the entire canopy gets covered in a more evenly. The lights can also be closer to the canopy, which again going back to the Inverse Square Law, means that you’re getting a more intense light, watt per watt compared to the first two lights.

So when you run two 260s you can spread them out from each other, hang them lower, and get more yield per watt.

I’m happy to sketch out an illustration of this argument, but it’ll need to wait until morning NYC time.


I pretty much understand exactly what your saying. Basis is that by spreading out the 260s, vs the 550 that is already at a set distance apart, you can cover more area to include more of the sides (widening the lighting overall). and for a rectangular shape like what I am going to have, then three 260s and a specific distance from one another and at a set height, will be able to get a more even spread across the canopy.

Also at a lower cost than having to have 2 of the 550s not only due to 2 less lights and 1 less driver, but cover same area with same spectrum, taking the overlaping of the 3 lights into account?


welp…I pulled the trigger on 3 HLG 260 kits…I will be returning the MARS Hydros…now what should I do for the seedling and or clone rooting, and up to week 2-3? the space I have set aside specifically for this purpose is 1.5’x1.5’x3’ tall…


If you’re just sprouting seedlings and rooting clones, you don’t need (or want) too much light. Something like an LED conversion bulb for an incandescent socket would probably be appropriate. I’d defer to @dbrn32 for temperature. I personally have an HLG 65 V2 for seedlings, but that covers a 2x2 and it cannot be dimmed. Probably more than you need, and in a bad way.


So one of those small $30 led light panels with only like 30-40 watts should be ok then?

1 Like

I like that!!