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Amazon (US/Canada): LetPot 100W Smart Plant Grow Light
International Customers: LetPot Official Website
Discount code: get 10% off with code ‘LPLIGHT10’
The LetPot 100W Smart Plant Grow Light comes securely packaged with foam inserts to prevent damage during shipping.
Setup & Build Quality
Setup and assembly is quite straightforward – the articulating arm is identical to a typical desk lamp. Adjusting and locking the light panel is achieved by tightening the ball joint. The base is a comfortable weight: it doesn’t feel like it can topple over easily. I also appreciate how the base is flat so it can be tucked under a chair or plant pot, which adds further stability.
The grow light panel is connected by a ball joint that can be set in place using the tightening collar.
Heat is often a problem with high powered LED grow lights so LetPot uses two heat-dissipating metal grids and vents on the back side of the light panel. There are also two handles on opposite sides of the panel that allow you to easily position the light. To be fair, even when the grow light was on for several hours, the back of the panel was only slightly warm to the touch.
The wired remote controls a few functions (the app controls far more – we’ll discuss later) but the most convenient thing was how it can connect magnetically to the stand – it’s not just dangling from the grow light!
Specifications & Performance
The array of LEDs comprises 240 chips: 128 white (5000K white), 48 red (660 nm), and 16 blue (450 nm). Using the app, you can dial in the red and blue separately from the white. Thankfully, the spectral distribution isn’t a big deal for tropical foliage growers (typical houseplants). As such, you can set the mix of colors so it is also comfortable for ambient lighting – no need for weird purple lights!
My spectrometer displaying measurements for PPFD, FC, lux, color temperature (CCT), color rendering index (Ra), dominant wavelength (nm), and the spectral power distribution (SPD) – all in the palm of my hand!
The light quantity is impressive and suits various growing applications. At maximum power (using the app to make all light settings 100%), the PPFD measured at 6″ from the center was 1200 µmol (~6300 FC). At 12″ – 550 µmol (~2900 FC) and at 24″ – 170 µmol (~890 FC).
Measuring the strength of the light at the leaf (in FC, left or PPFD, right) is essential to know whether your grow light is positioned correctly. You can’t rely on specs alone.
While it’s nice to have PPFD/FC values at various distances, you’ll be a more confident grower when you are able to measure the light strength in your actual growing situation. Get yourself a light meter so you’ll know how much light your plants are actually getting – I designed this one but most others will work just fine.
How much light does your specific plant actually need? For this, you’ll want to check out my article ‘Grow Light Strength Recommendations by Plant’ – where you’ll find a table of many common houseplants and recommended PPFD/FC values. In general, for starting seedlings or sustaining high-light plants like succulents/cacti, the LetPot grow light will work well within 12″ to 24″. Most of your tropical foliage houseplants will happily grow farther away, where the strength still hits the 400-800 FC range (80-160 µmol).
App Controls
The controls available on the remote are somewhat limited, which is understandable so as to keep the number of buttons manageable. Thankfully, LetPot has an app that allows much finer control such as red/blue spectrum, overall light strength, and duration. Connecting the app to the grow light was straightforward through Bluetooth.
In ‘Normal Mode’, you can adjust the overall brightness in 6 steps, set the on/off schedule, and customize the ‘Lightup Mode’. This setting is where you can have the light turn on immediately or gradually, simulating sunrise and sunset. While I don’t have any empirical evidence on whether this is beneficial for the plant, it’s definitely less jarring for the humans in the room! The duration of the gradual turning on and off of the light can be specified – by default, it is 30 minutes.
When you turn on ‘Custom Spec’ mode, The 3 types of LED chips (white, red, and blue) can be independently adjusted.
A small detail that I appreciated: when using the app or the wired remote, the grow light ‘beeps’ to confirm that it has received the command – it’s nice to have feedback.
(Left) The main screen in the LetPot app is clean and functional, giving you access to all the settings in one place. (Right) In Custom Spec mode, the sliders control the strength of each type of LED.
Practical Use
In my household, window space is at a premium, especially now with a toddler who’s toys are gradually taking over the living room! Some plants must therefore, be moved to other place and lighting be supplemented – or entirely replaced with grow lights. My rabbit foot fern planted in a basketball was always under the shadow of my huge Monstera.
My rabbit’s foot fern gets only 80 FC in this spot below the Monstera (whose leaves are getting 200-300 FC).
Now, using the LetPot grow light, I can move the plant to its own location in the far corner of my basement office.
In this setup, at half power, the plant is getting over 800 FC (160 µmol) – let’s calculate the Daily Light Integral if the grow light is on for 12 hours a day:
- PPFD is about 160 µmol/s/m²
- Converting this to an hourly rate: 160 x 60 x 60 = 576,000 µmol/h
- Converting µmol to mol: 576,000 / 1,000,000 = 0.576 mol/h
- Multiplying by 12 hours a day: 0.576 x 12 = 6.912 mol/day
So the DLI in the new location is around 6.9 mol/day, which will result in much stronger and faster growth! I just have to remember that stronger light means faster water and nutrient usage. So under this grow light, I will need to pay closer attention to when the plant needs to be watered.
Verdict
The LetPot 100W Smart Plant Grow Light is a versatile grow light. The stand allows for a variety of lamp positions while the app lets you dial in the precise power level for your plants. Growers of tropical foliage will find this grow light very adequately powered for a wide area under the light while high-light plants (succulents and cacti) will grow well on a tabletop where the strength can easily reach 2000 FC (400 µmol). I’m sure my rabbit’s foot fern will greatly enjoy the rest of the winter with this grow light!
Discount code: get 10% off with code ‘LPLIGHT10’
Amazon (US/Canada): LetPot 100W Smart Plant Grow Light
International Customers: LetPot Official Website
