Flexible LED strips as grow lights?

[Aluka]

Get a olanted tank and keep dwarf shrimps

[seaj]

Aluka, I'm so jealous! I really want to make my own Iwagumi style shrimp tank, but I have no place to hide such a tank. Maybe I can sneak in a small 2 gallon opae ula tank. I could probably get away with a terrarium just for plants. I'd really like to get some of those micro orchids, as well as some micro sinnnigias and micro African violets.

Naoki, does Philips make any lower powered LED strips that match the light output of a T8? Ones that are efficient? I can see other types on their site, but I can't decipher their specs. I'm now thinking that I could use that high powered one you posted about to grow some mini haworthias and gasterias. I could probably fit a whole collection of those under a single strip.

[naoki]

seaj, with LED, you can just use lower current drivers to get less total output. I used 900mA driver to get 22.7W for the 2' strip. You can use 600mA driver to get about 1/3 less light.

Indeed, using a lower current driver is a good thing; the LEDs operate at a higher efficiency. This is the reason why there is a trade-off. The cheap light doesn't want to use lots of diodes, so they drive a few emitters at a higher current. In this way, you can get enough light with low cost of fixture. But you are sacrificing the efficiency, and some cheap fixtures aren't any better than the florescent light in terms of efficiency.

With XF-3535L, there is a less dense version. Mine has 56 LEDs in 525mm length, the less dense version L235-4080AHLGBBAC0 (4000K, CRI=80) uses 36 diodes in 600mm. If you use 600mA driver (which is the reference current for this less dense model), it consumes 10.8W (about 1/2 of what I used). To me the denser model is a better deal ($19.37 for the 525mm model vs $14.50 for the less dense 600mm model). So if I were you, I would pay extra $5 for the denser model, and drive it at a lower current for really high efficiency (>147 lumen/W).

How big is your grow area? 2 bulb T8 is similar to 1 bulb of T5HO. With dense XF-3535L, my measurement shows that it is slightly more than 1.5-2 bulbs of T5HO when it is using 22.7W. So I don't think that it is too much light. At 1', it was giving 110 micromol/m^2/s of PAR at the very center (it drops off as you go away from the center), which is pretty good for low light plants like Paphs and Phals. Since AV requires a bit less light, if you set it at 18", you'll be getting about 50 micromol/m^2/s, which is probably good for AV?

Alternatively, there are dimmable drivers, but I usually don't use them. It costs a bit more, and "generally" efficiency goes down.

[seaj]

I am trying to light shelves that are 48" wide and 18" deep. I'd prefer to use 2 weaker strips instead of one stronger strip to provide more even light through out the shelf, and to promote better symmetry. African violets look best with perfect rosettes, and they require less rotating when the lights are directly above the plants. I am also trying to conserve vertical space, so I'd rather not use a single strong fixture that must be placed high above the plants. More shelves = more space for plants! I'm not too concerned with light falloff since happy violets are generally flat.

On the other hand, streptocarpus are not flat, and would probably enjoy a fixture placed a little higher. What hardware would you reccomend to power the 1150mm long strip to get max output, without sacrificing efficiency?

Thanks for all this help Naoki! I need to learn more about currents and drivers before this all makes sense, but I'm enjoying this technical stuff.

[naoki]

I looked up light requirement of AV, and they say 800-1000fc. Using this conversion, it is 116-146 micro mol/m^2/s.

So 1 strip of 1150mm model (which has the same density as 525mm model) is appropriate at 1' distance. However, I understand that you want to have 2 strips in parallel to minimize rotation of plants.

Availability of 1150mm model seems to be getting better, but it is still more difficult to get. Currently, 3000k is available for $38.28 from here.
This search engine is useful to find LED parts.

The nominal driving current for the 1150mm model is 900mA at 36V. But if you want to drive them soft, you can probably go with around 700mA, and it will be close to what you want. There are several ways to do this.

1) each strip is driven by a separate driver (700mA 36V driver x 2).
2) 2 strips are connected serially and driven by a single driver (700mA 72V driver x 1).

driver+  -----  +LED-  --\
driver-  -----  -LED+  --/

HLG-60-H-C700 can do it. It is efficient, and dimmable, but it is expensive ($45).

3) 2 strips are connected parallel and driven by a single driver (1400mA 36V x 1).

driver+ --- +LED- --- driver-
         \- +LED- -/

LPC-60-1400 can do it, and it costs $17.50.

Those Mean Well drivers are "name-brand" products with good quality. But there are some eBay or aliExpress drivers from China, which have good efficiency for around $12 (shipping included) for the option (3). They are usually called 50W driver. I can find one if you are interested in this route.

Frequently, (1) or (2) is used for connecting LED in general. But in this case, parallel connection (3) is safe. With parallel connection, if the wire to 1 LED breaks, all current goes to 1 LED strip. But since you are using lower current, it can handle it (Max current for the model is 1800mA, so 1400mA is below the max). So option (3) is the more economical route.

[Norden]

Sorry for the question, but are LED grow bulbs found on Amazon worth the price? Does anyone know if they function as grow lights with the correct spectrum and intensity? I am looking to provide some extra light to my orchids, and idea of a clamp light fixture with an LED bulb sounds great.

[Tschimm]

Welcome to the forum Norden.
There are many many threads about LED lighting . Just use the search function and browse through.

If you have specific questions afterwards, we'll be happy to answer them ;-)

[Doofinator]

Hi All,

I have one window in my whole house that gets enough light to support Phal growth. And that window sill is full. I've purchased under cabinet lighting from Inspired LED and had it installed in my kitchen in 2013 (LED Lights | LED Light Manufacturers | Inspired LED). I'm wondering if they'd be suitable for orchid or fresh herb growth. They have a dimmer, and I thought the price was very reasonable:

$100 for 163.5" of LED (warm white, 3200K)
$65 transformer
$45 Lutron Dimmer
$22 cables and clips
free shipping

However, these prices are from summer 2013. Thoughts?

Thanks,

Em

[Subrosa]

Herbs are best grown in full sun. They might grow under your lights but it's hardly an optimal situation for them. On the other hand there's almost certainly an orchid well suited to your lights. Your job, find it!

[NYCorchidman]

Try and see how the plant grows. If it looks fine, then it's fine. lol
If it flowers under that light, then you know for sure that it works.

I flowered phals and paphs under my LED (meant for plants) and I flowered tolumnias (high light orchid), mini oncidiums and paphs under halogen lamp that people use for reading at night.

So, try and you might be surprised.