Your Complete Guide to Grow Lights – With Grow Gang!

We caught up with Lorenzo from Grow Gang, a passionate indoor gardener and founder of the UK-based grow light brand making waves across the houseplant community. Born out of London flats lacking natural light during the pandemic, Grow Gang began with a simple desire: to stay connected to plants and nature, even when outdoor space was nonexistent. What started as a mission to create a beautiful, functional grow light became the Pianta, Grow Gang’s flagship product, now a go-to for indoor growers across the UK.

Do grow lights really matter?

When growing tropical plants indoors in the UK, natural light is often not enough. The average UK living room has a surprisingly low light intensity, especially through autumn and winter. Meanwhile, most tropical plants evolved to thrive in brighter conditions, soaking up filtered sunlight beneath rainforest canopies. Think rays sneaking through a dense rainforest canopy, not the dim corner of a Victorian terrace.

Plants like Philodendrons, Anthuriums, and Alocasias might tolerate low light, but they really thrive in bright, indirect light. Without adequate light, even the healthiest plants will slowly decline, leaves droop, variegation fades, and growth stalls.

But with the right grow light, your plants will be happier than ever and reward you with happier, fuller growth.

This blog outlines everything you need to know about choosing the right growlights, with help from Lorenzo (photographed below!)

Types of Grow Lights

“In my view, LED is the only serious option now. They're miles ahead in energy efficiency, longevity, and precision. You can tailor the light spectrum to suit your plants without running up your electricity bill. Fluorescents and incandescents are being phased out anyway.”
– Lorenzo, Grow Gang

LEDs

Energy-efficient, long-lasting (up to 50,000 hours)
Available in full-spectrum or custom red/blue blends
Stay cool, safe for leaves
Ideal for any setup, from shelves to statement floor lamps

Fluorescent

Still used for propagation or budget setups, but being phased out:

T5 tubes are useful for seedlings, but not energy-efficient
Create a lot of heat, which may not be suitable for all plants
UK/EU regulations are ending most general-use fluorescent lighting
Still legal for specialist use like horticulture, but stock is dwindling

Incandescent

Not recommended.

Inefficient, short-lived, and produce excessive heat
Starting to become obsolete and no longer sold for general use in the UK

Note: The UK has phased out incandescent bulbs since 2009 and is phasing out most fluorescent lighting under Ecodesign and RoHS directives. Specialist bulbs (like grow lights) are still allowed under exemptions, but manufacturers are shifting focus to LEDs.

What Should a Beginner Look for in a Grow Light?

“Look for something simple, with high light output and a full-spectrum LED. I think it’s important that you feel comfortable having it in your living space, and it should look good. If it’s clunky or harsh, you’ll end up hiding it away, and then it’s not helping anyone.”
– Lorenzo, Grow Gang

Alongside aesthetics and ease of use, a few tech specs are worth checking:

PPF (Photosynthetic Photon Flux) – Measures the total amount of plant-usable light emitted per second, in micromoles (µmol/s).
PPF/W (efficacy) – Shows how efficient the light is, i.e. how many micromoles of light you get per watt of electricity. Aim for 1.6 µmol/J or higher for top-tier LEDs.

💡 Tip: Wattage tells you how much energy the light uses, but not how much useful light your plants actually receive.

While PPF tells you the total light output, PPFD (Photosynthetic Photon Flux Density) measures the light intensity that actually reaches your plant's leaves, crucial for placement and positioning. It's measured in micromoles per square metre per second (µmol/m²/s).

You don’t need to measure this in most situations; a bit of trial and error works really well. But if you want to be more precise, you can use a PAR light meter or even a smartphone app to check light levels at different heights or times of day.

What’s a Common Mistake People Make When it Comes to Grow Lights?

People are often worried about burning or scorching their plants, maybe they’ve heard a few horror stories. And yes, it is possible if a grow light is placed very close or left on for too long. But in reality, most setups we see could actually benefit from moving the light a little closer, if the plant can handle it. Closer placement increases light intensity, which many tropicals need to really thrive. And remember: consistency in your daily light cycle is just as important as brightness. An automatic timer can make that part effortless.
– Lorenzo, Grow Gang

How Do I Choose The Right Lighting?

Every space has different needs. Here’s how to decide what suits you:

If you’re growing in a small shelf or cabinet:

Choose a compact adjustable LED, like the Pianta clip on bundle, or a light bar design that can fit in the shelf space.

For an open room or living space:

Grow light bulbs like the Pianta can work really well, or consider a pendant grow light that hangs from the ceiling like the Claria grow light. Just keep in mind: using a grow light bulb in your main ceiling fixture isn’t always the best option, the light needs to be positioned close to your plants and directed at them, not diffused across the room like a normal light.

For different plant types:

Aroids love moderate light give them consistent 10–12 hr exposure with a mid-height full-spectrum light.
Succulents and Cacti prefer brighter conditions and higher light exposure during the day. Position lights closer (20–40 cm) use powerful grow lights for long cycles 12- 16 hours, and ensure ventilation.
Cuttings or props do best with slightly more gentle, consistent light while rooting. Aim for 10–12 hours a day with a full-spectrum light positioned at a safe distance to avoid stretching.

Budget Tip:

You don’t need to buy the most expensive grow light out there, but it is worth investing in one that’s energy-efficient and well-built, so you save on electricity and don’t have to replace it after a few months.

“The Pianta is ideal for new growers, it’s subtle, affordable, and powerful. If you want something more design-led for a living room, the Claria is very popular”
– Lorenzo, Grow Gang

How many hours should my grow light be on for?

As a rough rule of thumb to effectively mimic the sun's natural light it should be on for 8- 16 hours a day however if there is already a lot of natural light, it can be used for just a few hours a day to top up the light and keep the plant thriving.

Even plants need a good night's sleep! Make sure not to run the light for longer than 16 hours a day so your plants can rest.

💡 Tip: Most tropical plants love 10–12 hours of consistent light. If you’re unsure, that’s a great place to start.

How far should a grow light be from my plant?

It depends on what grow light you're using, but as a very rough guide 30–50 cm away is a safe range to start. Watch for stretching (too far) or burning (too close).

Timers are your best friend. Smart plugs and apps help automate routines.

"Consistency beats intensity."

A steady cycle every day, even at lower brightness, is more effective than a random burst of blazing light.

Myths, Mistakes, and Must-Knows

Myth to bust:

“You need purple grow lights to get results.”

Not true. Full-spectrum LEDs support all stages of plant growth, mimic natural sunlight, and make it easier to spot pests or issues, without turning your home into a nightclub or looking like a suspicious grow set up.'

Bonus Tip: Mind the Distance

Light intensity doesn’t drop off gradually; it follows the inverse square law. That means if you double the distance between your grow light and your plant, the light intensity actually drops to a quarter of what it was. Even a small shift in height can make a big difference, especially in low-light setups. If your plants are stretching or not thriving, try nudging the light a little closer (as long as they’re not getting scorched).

Shop Grow Gang’s favourite grow lights at GrowTropicals!

Follow @growgang.store for more grow tips, setups, and tropical plant inspo

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