HPS Lights: The Classic Light for Indoor Growing

HPS Lights: The Classic Light
For Indoor Growing

Introduction: HPS lights are the traditional staple of growing indoors. Growing indoors is one of the first choices many have when their state legalizes. When you put the overall cost of doing it yourself versus the overall cost of purchasing at your local retail store, the numbers are shocking.

On top of that, many residents need to wait for their first local shop to open near them. Why wait when you can do everything yourself and save approximately 90% of retail costs?

Why Are HPS Lights So Popular?

High-Pressure Sodium lights (HPS) have been the traditional go-to for many avid indoor cultivators. In the 70’s these lights were all the rage. It allowed growers to have the optimal light spectrum for their plants.

Due to the heat that these lights generate, many growers have found that cooler areas in the house such as a basement or garage are the perfect location for their indoor grow. This allows for a more stable and accurate climate for your plants.

Although these benefits are great, there are a few drawbacks to using HPS lights.

Technological Advancements In Lights

HPS lights use a large amount of energy – which can increase your energy bill. As mentioned before, they generate a lot of heat, thus generating more power in order to function.

We have come a long way since the 70’s. With the rising national acceptance of your plants, comes rising technological advancements. Light technology is moving for lower cost and larger effective light spread. Since the introduction of HPS lights in hydroponic stores, the industry has gone through multiple renaissances for optimal performance.

While many prefer to go this route, the use of High-Pressure Sodium lights is still popular. While it may add a little extra to your energy bill, the outcome is still regarded as one of the best-performing lights for beginner growers!

This post was brought to you by nhcannanow.

LED VS HPS Grow Lights

HPS Grow Lights

What lights do professional growers use? Crops require at least 5,000 lumens of light to mature and produce a satisfactory harvest. In addition to lumen output, cultivators also make their decisions based on setup and operational costs. Here’s a breakdown of LED Grow Lights vs HPS.

Can LED Replace HPS?

A majority of indoor farmers prefer LED grow lights because they outperform High-Pressure Sodium bulbs by at least 50%.

On the other hand, HPS grow lights are a feasible option for crops that require little variation in UltraViolet (UV) light to perform photosynthesis or nurture flowering.

This is why some commercial and small-scale cultivators prefer HPS to LED grow lights to save on costs.

Purchase and operational costs are crucial factors when analyzing LED grow lights vs HPS.

LEDs cost twice as much as HPS grow lights and this makes it hard for the diodes to kick out High-Intensity Discharge (HID) bulbs from the market.

Cultivators growing in frosty climates use HPS to generate warmth consistently for the crops. Optimum temperature enables plants to perform photosynthesis and absorb nutrients through the roots.

What LED Grow Light

Is Equivalent To 600W HPS?

A cultivator considering switching to LED should purchase a 200-watt panel to replace a 600-watt HPS grow light. LED panels produce 90,000 lumens just like the 600W HPS bulb while reducing electricity consumption by 50 percent. The farmer stands to gain a higher return on investment by replacing the HPS with an LED grow light.


It’s advisable to use a 400-watt LED panel when replacing a 1,000-watt HPS grow light. It’s not unusual, however, to come across 300-watt LED grow lights that produce over 110,000 lumens.

This range of LED grow lights produces less heat than HPS bulbs and is designed for 4 x 4 grow tents.


Below is a step-by-step comparison of both sources of light.

Cost Of Purchase

High-Pressure Sodium lights are highly affordable for individual and commercial farmers compared to LED grow lights. On average,  a 400-watt LED panel costs around $600-$700 while an HPS bulb with similar output ranges from $250-$300.

Electricity Consumption

Horticultural companies in the 70s gravitated towards LED grow lights since the panels consumed only a third of the electrical energy used by HPS bulbs. In addition to lower power consumption, LEDs generate a higher return on investment because they stimulate a higher rate of photosynthesis for crops, leading to better harvests than HPS grow lights.

Heat Regulation

HPS grow lights emit 50°F more heat than LEDs. This difference in temperature compounds when several crops are grown under HPS bulbs. The cultivator usually has to purchase an industrial air conditioner to cool down the grow room. The crops also face a higher risk of dehydration during hot summers.

LED grow lights emit less heat and this is why most grow rooms and tents use a set of fans to provide air circulation and regulate temperature. The low heat emission makes LEDs safe for nurturing clones and seedlings.


1. Affordable Source of Full Spectrum Ultraviolet Light

High-Pressure Sodium bulbs have built a strong reputation among horticultural farmers since the 50s. Its ability to provide powerful full-spectrum UV light makes it more reliable than fluorescent and metal halide bulbs. Some grow kits even come with HPS grow lights as an alternative to costly LED panels.

2. Provide Deep Penetration Of Light

Crops need sufficient UV light covering top to bottom to maximize yield production. HPS grow lights are reliable for growing plants that reach up to six feet tall since the bulbs emit powerful omnidirectional wavelengths. Foliage located at the bottom of the canopy benefits from such light and this results in a healthy plant.

3. Improves Microbial Activity in The Soil

Microbes reside in the soil and are beneficial to farmers because these tiny organisms break down manure into nutrients that are easily absorbed by plant roots. Optimum warmth inside the soil stimulates microbes to perform their role more efficiently. The heat emitted by HPS bulbs enables the soil to retain warmth consistently.


1. Consumes More Growing Space Than LEDs

Cultivators are keen to maintain a three to four-foot gap between crops and overhead HPS bulbs to protect the plants from heat stress. This shortcoming makes it difficult to maximize returns on investment since the farmer wastes a lot of space by preventing plants from getting taller and producing more harvests at the apex.

2. Large Scale Cultivators Require Expensive Dehumidification

Cultivators running large grow rooms or tents fitted with HPS grow lights also have to spend extra money on dehumidification. As the plants transpirate, humidity levels increase significantly. The heat emitted by the HPS bulbs combined with the increased humidity can create a conducive environment for mold infestation. Large dehumidifiers can solve the humidity problem, however, this translates to increased overhead costs.

3. Requires Experienced Cultivators For Confined Grow Spaces

Nurturing crops inside a grow tent requires a keen eye on humidity and temperature control. It takes several years of cultivation to know how to control these variables, especially while using  HPS grow lights. Unlike LEDs, HPS bulbs have little room for error. If the cultivator lets the plants grow tall, the canopies will wilt due to overheating.



1. Enables Cultivators To Optimize On Vertical Space

LED grow lights suspended above crops require a distance of two feet to protect the canopies from excess heat. The reduced heat production compared to HPS bulbs, allows plants to grow much taller and produce higher yields. It’s one of the reasons why LED growers enjoy harvests that exceed HPS production by at least 50 percent.

2. Maximizes Space and Light Usage

Cultivators using LED grow panels switch from broad-spectrum white UV to deep purple light to promote flowering. This is based on scientific research that explains how plants utilize different wavelengths of light as they transition from seedlings to mature crops. Stimulating the rate of photosynthesis enables the crops to direct energy and nutrients toward bud sites and this contributes to impressive harvests.

The ability to switch wavelengths enables crops to maximize the lumens produced by the LED grow lights. This allows the farmer to harvest higher yields per square foot of growing space compared to HPS bulbs. In other words, LED grow lights deliver a better ROI since they enable plants to maximize lumens and run on one-third of the electricity required by HPS.

3. LED Grow Lights Are Compatible With Remote Control

Technology has made indoor cultivation much easier thanks to grow apps that enable cultivators to remotely control certain variables. This innovation leans heavily towards grow tents or rooms that use LED grow lights. It makes it easier for first-time growers to understand how crops respond to various wavelengths and enables them to set light cycles through the phone or an iPad.


1. Transitioning From HPS to LED Is Expensive For Commercial Growers

While it’s true that LED grow lights require only one-third of the power used by HPS bulbs, the purchase costs are expensive. A broad spectrum 720-watt commercial LED grow panel costs from $600 yet the grower needs about three to four panels to replace an HPS system.

2. High Volume Of Counterfeits In The Market

There’s hardly any barrier to entry for manufacturers or retail sellers in the horticultural lighting market. Dishonest dealers publish fake product reviews online and use cheap-pricing strategies to con farmers by selling them inferior-quality LEDs. These unfamiliar brands also share scarce information regarding the manufacturer or country of origin. In addition, cultivators also have to watch out for replica brands mainly advertised on social media.


Looking back at the pros and cons of each device, the diodes emerge on top as far as LED Grow Lights vs HPS goes. Excessive heat, which, unfortunately, plagues HPS lights, affects yields because it limits the crop’s vertical growth. Warehouse spaces are costly, which is why only a few growers can afford to lease them.

The ability to provide a combination of light spectrums promotes bud growth at a higher rate than HPS grow lights. Despite the recent upgrades implemented by High-Intensity Discharge (HID) bulbs manufacturers, the LED’s grip on the market remains untouchable. This ability to promote photosynthesis at the highest level motivates customers to pay top dollar for LED grow lights.

LEDs maximize ROI by enabling each plant to produce a higher yield per square foot compared to HPS grow lights emitting similar lumens. When you consider the low energy consumption, it makes financial sense to invest in LED grow lights.

To check out all of our available lights, check out our Grow Lights page.


Fluorescent vs LED Grow Lights

Fluorescent vs
LED Grow Lights

Fluorescent grow lights produce a combination of light spectrums aimed at promoting photosynthesis. They also allow the plants to achieve maximum height since they emit low heat compared to High-Intensity Discharge (HID) grow lights.  Do these features make fluorescent a suitable alternative to LEDs? Here’s a complete breakdown of LED vs fluorescent grow lights.

LED vs Fluorescent Grow Lights

LED grow lights are diodes or semiconductors that emit a combination of blue, green, orange, and yellow UV light for horticultural use. This technology stands out because the light produced is the closest replica to sunlight compared to fluorescent or HPS bulbs. In addition, some models have features where farmers can activate purple UV light for nurturing flowering plants.

Advantages of Led Grow Lights

LED grow lights are diodes or semiconductors that emit a combination of blue, green, orange, and yellow UV light for horticultural use. This technology stands out because the light produced is the closest replica to sunlight compared to fluorescent or HPS bulbs. In addition, some models have features where farmers can activate purple UV light for nurturing flowering plants.

Compatible With Smartphones

Recent innovations have produced LED grow lights that allow farmers to control light cycles and intensity remotely. After setting up the panel, a grower downloads an app and connects to the LED through Wi-Fi. It’s quite a life-saver for cultivators traveling long distances and might forget to activate flowering or regulate light intensity. The same feature is crucial for first-time growers who are still learning the ropes.

Compatible With Compact Spaces

LED grow lights are popular in compact-size grow kits, such as the 24 x 24-inch model since crops can thrive without experiencing heat stress. This advantage makes LEDs a safe bet for novice cultivators eager to learn about indoor growing while nurturing one or two plants.

Requires Minimum Dehumidification

A cultivator using HPS lights inside a 4 x 4 grow tent needs to create space for a dehumidifier. The accumulation of heat produced by the bulb and moisture released through transpiration nurtures mold spores into full-blown fungi. This additional equipment results in the farmer paying expensive power bills. LED grow lights only produce 33 percent of the heat emitted by HPS bulbs. This edge reduces the need for a dehumidifier except during winter when external humidity increases significantly.

When Should You Use an Led Grow Light?

Plants that grow tall and develop thick bushes require penetrative light reaching the undergrowth to maximize yield production. It’s also crucial to have a grow light that adapts to the crop’s flowering stage. Peppers, for instance,  flourish under a light that’s rich in red wavelengths. Tomato plants produce large fruits when exposed to red and blue wavelengths.

High-Intensity Discharge bulbs consume 70 percent more energy than diodes. A 200-watt LED produces a similar amount of lumens emitted by a 600-watt HPS bulb. Their inability to produce different wavelengths of light limits yield production, making them an expensive option for illuminating large areas.

What Are Fluorescent Grow Lights?

Fluorescent grow lights contain mercury vapor and a white phosphorous coating inside the bulbs. They’re used to nurture seedlings or plants that require a low amount of UV energy. These bulbs come in two designs, the most popular being the Compact Fluorescent Light (CFL). Tubes come in different diameters such as the T5 and T8. Light is produced when electricity passes through the electrodes and stimulates the mercury atoms to move vigorously. This movement produces ultraviolet light which becomes brighter as the wavelengths pass through the phosphorous coating.

Can You Grow Plants With Regular Fluorescent Lights?

Yes, you can germinate seeds using regular fluorescent bulbs because they produce heat and light that are conducive for seedlings. In addition, some houseplants require a moderate amount of UV light to carry out photosynthesis. As the seedlings transition into a vegetative state, the cultivator has to purchase alternative grow lights for the crops to grow strong and healthy.

Advantages of Fluorescent Grow Lights


Fluorescent grow lights are highly affordable and easily accessible at any store. The light fixtures cost less than $100, making this option the most affordable compared to HPS and LED grow lights.

Allows Maximum Vertical Growth

Seedlings can grow without experiencing heat stress when a CFL is suspended two inches above the soil. As the plants grow taller, the farmer maintains a two-inch distance between the bulb and apex.

Reliable Source Of UV Light

A 26-watt CFL bulb provides green and yellow light wavelengths that are necessary to promote photosynthesis. This process provides seedlings with sufficient energy to develop healthy roots. The wavelengths produced by CFL maximize the growth of foliage and improves the plant’s chances of survival.

When Should You Use a Fluorescent Grow Light?

Cultivating Crops That Require Low UV Energy

Kitchen herb gardens require a moderate amount of UV light to cultivate crops into maturity. The average duration for most herbs is three weeks. It makes sense to purchase a couple of T5 or T8 fluorescents to supply light because their low consumption of electricity makes them affordable compared to HPS or LED bulbs.


Seedlings require UV light to perform photosynthesis and develop healthy roots. Fluorescent lights enhance the success rate of germination by providing warmth to the soil. In addition to boosting microbial activity, the heat activates the seedlings’ metabolism.

Nurturing Houseplants

Green plants are common inside home yoga studios because they increase fresh air supply and enhance aesthetics. A homeowner can enjoy vibrant greenery throughout the year because CFL bulbs are low maintenance, and provide sufficient UV light that’s beneficial for photosynthesis.

Purchase Super Soil

Purchase Premium Nutrient Rich Soils and Super Soil and Supper Items

Introduction: When planning on growing cannabis it’s important to plant your seeds in the highest quality nutrient rich environment, we strongly recommend you match your seed with the best possible organic soils, nutrients and super soils for an optimal yield.  We recommend using a nutrient rich soil that will be able to manage the demands of the most extreme growing environment.

What is Super Soil and why should you use it?

CaliSuperSoil is a perfectly balanced, 90-day fermented artisanal super soil that is suitable for both photoperiod and autoflowering strains. Formulated through years of research and development, resulting in an optimal organic blend that’s unmatched. Our super soil is built from an 18+ amendment blend that ensures that your crop thrives from seedling all the way to harvest. This comprehensive nutrient-layered soil is designed to make growing as easy as possible, eliminating the need to frequently mix nutrients or add supplements.

What are the benefits?

Growing cannabis in a demanding artificial environment requires an enhanced nutrient solution to aid in the growth of a modern cannabis grow, The demands of a modern grow are very different to an outdoors natural grow.

  • Cali Super Soil offers approximately 800% more nutrients availability to your plant’s roots than regular potting soil
  • Superior Ingredients: Through our selection of the best organic soil amendments the state of California has to offer, we can guarantee that every bag of CaliSuperSoil contains only the highest-quality nutrients direct from mother nature.
  • An Artisanal Process: We steam-blow our base soil to ensure purity and hydration at the molecular level before the fermentation period begins.
  • Aged: They say ‘Good things come to those who wait’. But who has time to wait these days? We do, for 60 days, and it makes all the difference. If you are looking for a super soil solution bursting with billions of living micro-organisms just waiting to get to work, we are here to provide!
  • No Fillers: Our products are 100% free of any low-grade mixing fillers. Competing products are often manufactured from, less expensive, non-organic ingredients that can actually cause more harm than good.
  • Expertly Hand-Crafted: Super Soil is a living product. That is why every single bag of CaliSuperSoil is expertly hand-crafted, you will only find experienced horticulturists working “hands-on” with our products to ensure the highest standards, industry-wide.

What should I buy to manage my grow?

  • Cloth Pots – 3,5 or 7 gallon pots – the bigger the pot the bigger the plants/grow cycle but the slower it will grow.
  • Fermented Calisupersoil: Extrema nutrient filled soil: Around x800 time more potent than regular potting soil.
  • CaliSuper Soil – 6lb bag
  • CaliSuper Soil – Premixed pots: 3 or 5-Gallon
  • Fox Farm soil, ocean forest – strong dependable soil to enhance your grow: 1.5 SU.FT
  • Rapid rooters: Early seedling root enhancing with growth nutrients: 5 pack