Grow Lights – House Plant Journal



Disclaimer: this is a paid partnership between Soltech Solutions and House Plant Journal.  The products were given to House Plant Journal to provide an honest review.  Using the links to purchase from Soltech supports my efforts to create educational content on House Plant Journal.

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The Soltech Grove LED Bar Light comes in black and white.

Impressive by build quality

Right from the unboxing and holding the unit in my hands, I was impressed with the build quality.  The entire unit feels solid and nice to touch – there’s something satisfying about the feeling of the textured aluminum body that houses the LED chips.

The frosted cover is a nice touch that both hides the raw LED chips when the light is off or at the dimmest setting.  The light is also more evenly distributed within the coverage area.  The overall light housing is sleek and stylish – something you would want to display in your living room.

The bulb tube is connected by strong magnets to the two mounting brackets.

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To turn the unit on or off, you double tap anywhere on the tube – about as fast as a double click on a mouse.  To adjust the brightness, you double tap and hold, which will cause the brightness to go down or up by 10 levels.  This is useful if your plant does not require the maximum brightness but the light is mounted in a small shelf (more on measuring and why this is so critical later).

To help you “set it and forget it”, Soltech includes a wall-mounted timer where you can set the daily on/off duration.  Typical durations for foliage plants would be 12 to 18 hours per day, which depends on your desired Daily Light Integral (DLI) for your particular application.

The Light

The light appears as “warm white”, which is around 2500-3000K.  This will be comfortable on your eyes and will look similar to your other household lights.  The color temperature of typical “white” lights ranges from 2500K (“warm white”, orange tint like a fireplace), to 5000K (“cool white”, more blueish, sterile feeling).  Some are even as high as 6500K, which is a very blueish light.  In terms of growing houseplants, color temperature does not have a major impact on growth – the measured strength is what matters.

Measuring the strength of the light that reaches your leaves is critical – you wouldn’t use an oven without knowing at what temperature it should be set.  Likewise, with grow lights, you need to measure the light reaching your leaves in order to set the distance and/or adjust the brightness correctly.

You can measure a white LED with a traditional light meter (in foot-candles, FC or lux) or a PAR Meter (in µmol/s/m², shortened to µmol) because FC and lux are well-correlated with PPFD.  This is not the case with all types of artificial light sources: the discrepancy between FC and PPFD is bigger when measuring ceramic metal halide, high pressure sodium, fluorescent, or pure red/blue LED.  The Soltech Grove LED Bar is a white LED light so you don’t need to worry about this – I will measure in FC.

In terms of spectrum, many people throw around the term “full spectrum”, but let me show you what it actually means using a spectrometer.

Here’s a fluorescent bulb that has a color temperature of 2474K (precisely measured by the spectrometer).  So this light would appear “warm white” to our eyes but look at the spectrum – very narrow spikes at specific wavelengths.
Now here’s the Soltech Grove LED Bar’s spectrum – it fills up the entire Photosynthetically Active Radiation (PAR) range (400 to 700 nm).  This spectrum is considered “full spectrum” and well-suited for plant growth.
Regular T8 bulbs (right) direct their LED outwards for maximum spread but, for a grow light, we want as much light to reach the leaves.  The Grove Bar (left) does this by limiting the beam angle keeping it narrow enough not to waste light but wide enough for the width of a shelf where you would put plants.

How to Use the Grove Bar Light

Very close range for small succulents: you could install it into a small shelf where the light would be within one foot of the plant, at maximum brightness. This could grow several small succulents very well.

Instead of the usual leggy fate of most echeveria, the grow light would provide sufficient light to keep your succulents nice and compact.  In this setup for 12 hours, the DLI is 10.4 mol/day (1 – full calculations at the end of the article).

I’m using the LTH Meter, the first device that measures light, temperature, and humidity all in one.  I designed the LTH Meter to empower plant parents to be more informed about their environmental conditions.

Different plants at different strengths: I’ve set up the Grove LED light in a set of floating shelves in my living room.  You can make use of the different strengths of light within the coverage area – higher light plants in the middle and lower light plants off to the sides.

When using grow lights, it is critical that you have a light meter so you know you’re placing the plant at the right distance – as you’ll see, mere inches can result in 2x or 3x difference in light levels even though the brightness setting of the light remained the same.

I have also created a reference table of light levels for various plants: Light Requirements by Plant

Plants on this shelf (left to right): Philodendron tortum, Tillandsia xerographica, Ledebouria socialis, and Peperomia puteolata.
On the other far end of the grow light, I’ve placed my Philodendron tortum, which also grows fine in lower light – here it is getting 200 FC x 12 hours (DLI: 1.7 mol/day) (2)
Air plants tend to prefer more light as well so I’m putting my Tillandsia xerographica right beside the Ledebouria socialis (Silver Squill).  The xerographica sits slightly lower than the Silver Squill, resulting in slightly lower light levels reaching the air plant’s leaves.  500 FC x 12 hours provides the plant a DLI of 4.3 mol/day (3).
The Silver Squill (Ledebouria socialis) grew very well outside in the warmer months so I want to continue pushing it while indoors.  Giving it 800 FC for 12 hours should do the trick!  This works out do a DLI of 6.9 mol/day (4).
Peperomia can grow well with 200 FC x 12 hours (according to my light requirements table) so I’ve placed this P. puteolata towards the farther end of the grow light.  From here, the plant sees about 200-300 FC.  The DLI from 250 FC x 12 hours is 2.2 mol/day (5)


After bringing in some of my favorite plants for the winter, I’m super excited to use the Soltech Grove LED Bar to keep them thriving *AND* stylish in my living room. The overall feel and build quality tells me this light will last many years.

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(1) 1200 FC x 12 hours
Convert FC to µmol/s/m²: 1200 x 0.2 = 240 µmol
Find total light for 12 hours: 240 x 3,600 x 12 = 10,368,000 µmol/day
Convert to mol: 10,368,000 / 1,000,000 = 10.368 ~ 10.4 mol/day

(2) 200 FC x 12 hours
Convert FC to µmol/s/m²: 200 x 0.2 = 40 µmol
Find total light for 12 hours: 40 x 3,600 x 12 = 1,728,000 µmol/day
Convert to mol: 1,728,000 / 1,000,000 = 1.728 ~ 1.7 mol/day

(3) 500 FC x 12 hours
Convert FC to µmol/s/m²: 500 x 0.2 = 100 µmol
Find total light for 12 hours: 100 x 3,600 x 12 = 4,320,000 µmol/day
Convert to mol: 4,320,000 / 1,000,000 = 4.32 ~ 4.3 mol/day

(4) 800 FC x 12 hours
Convert FC to µmol/s/m²: 800 x 0.2 = 160 µmol
Find total light for 12 hours: 160 x 3,600 x 12 = 6,912,000 µmol/day
Convert to mol: 6,912,000 / 1,000,000 = 6.912 ~ 6.9 mol/day

(5) 250 FC x 12 hours
Convert FC to µmol/s/m²: 250 x 0.2 = 50 µmol
Find total light for 12 hours: 50 x 3,600 x 12 = 2,160,000 µmol/day
Convert to mol: 2,160,000 / 1,000,000 = 2.16 ~ 2.2 mol/day

Article: references for DLI requirements by plant

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