Posted on

Sprouting cannabis seeds under 1000 watt hps

1000w HPS Distance From Plants

It is important to give your grow light and indoor plants the appropriate distance so they can flourish. Now, if you’re wondering what distance from your plants you should give 1000w HPS grow light, we will let you know in this post.

Various grow lights have different placements that need to be followed. High-pressure sodium (HPS) lights are great for providing lights for your indoor plants. Following the right positioning for this type of grow light is essential so you don’t end up causing harm to your indoor plants.

In this article, we will be looking at how far should 1000w HPS distance be from plants. We will also be looking at the appropriate hanging distance for other grow lights. So, continue reading to learn more about this.

Table of Contents

To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video

Hanging HPS grow light too low can burn your plants. Also, placing them too high can cause your plants not to receive adequate light supply making them grow leggy and stretchy.

Another criterion to look at when considering the distance to hang your HPS grow light is the power of the grow light. The stronger the grow light, the farther it should be from your plants.

So, for 1000w HPS light, the appropriate hanging distance from plants should be about 20 to 36 inches above your plant canopy. Then you can gradually move the light closer while monitoring them as your plant strengthens and develop. However, you should ensure the heat emitted is bearable for your plants so they don’t burn them.

You can do a simple backhand test by putting your hand between your HPS grow light and plant to feel the heat. If they don’t burn the back of your hand, then your plants are safe. Nevertheless, always do the proper adjustments if you notice any changes as your plants develop.

For seedlings, the 1000w HPS distance from plants should be around 5 feet. However, you should be very careful when using HPS for your fragile seedlings especially high power such as 1000w.

For other HPS grow light lesser than 1000w, the hanging distance will continue to decrease as the bulb wattage values decreases. However, various grow lights have their distance range to be followed.

Other Grow Light Hanging Distance

As we said earlier, various grow lights have a specific hanging distance that must be followed so your plants can grow optimally. Let’s take a look at how far fluorescent and LED distance should be from their plants’ canopy.

Fluorescent Light Distance From Plants

Fluorescent lights are one of the safest lights to use because they don’t emit too much heat compared to other grow lights. Therefore, they can be positioned close to your plant canopy.

You should hang your fluorescent grow light about 4 to 6 inches above the plant canopy for the vegetative and flowering phase. For seedlings, position your fluorescent grow light a little farther. You can do 6 to 10 inches for seedlings and gradually move them closer as they mature.

Also, note that when it comes to using fluorescent grow lights, anything higher than 12 inches from your plants’ canopy may mean your plants aren’t getting good light energy. This is because fluorescent light strength decreases when the height is too far from the plants’ canopy. So, ensure they are close enough to your plant as they are safe to be positioned close to plants.

How Far Should LED Grow Light Be From Plants?

LED grow lights are one of the most popular lights to use for indoor gardening. They are also safe to use at an appropriate close range on plants and they don’t emit much heat. LED grow lights are as well strong and efficient and can be used for different plant growth stages. They are majorly used in the flowering and fruiting stage.

When it comes to using LED grow lights, there is no particular rule to their positioning. But as a recommended tip, they can be placed around 12 to 18 inches above the plants’ canopy.

However, there are many types and brands of LED grow light that offers different output so deciding the appropriate distance may be tricky. The good thing is most times when you purchase LED grow lights, the manufacturer usually puts a recommended hanging height to follow. You can start with the manufacture’s recommended hanging distance.

After trying the manufacturer’s recommended hanging distance, you can go ahead and move it a bit closer to get the perfect distance. Do these until you get to a point where your plants start to bleach. Also, you need to always monitor your plants when trying new grow lights. Move them backward immediately you notice any discomfort in the plants.

By doing this, you must have mastered the right hanging distance for your plants for them to receive optimal lights for their growing needs. Also, you may need to adjust the grow light usually upwards as your plants continue to grow taller and develop.

How far should my 1000 HPS lights be from my plants?

If you look at a picture of a HPS (high pressure sodium) light fixture, you’ll notice that there are two metal reflectors, one on top of the other. This design keeps the heat from dissipating and helps to direct the light toward the plants. The light fixture itself is mounted on a stand with a ballast. You’ll find that the ballast is usually mounted between 8-10 feet from the fixture itself. The distance will vary depending on the type of ballast you purchase. Most people recommend a minimum of 15 feet of separation between plants and HPS lights. If you’ve got enough room, I’d say go for it.

What does the ballast do?

A ballast regulates the flow of power to the lamp, which provides a constant voltage and frequency to the lamp. The ballast usually includes circuitry for sensing lamp current and voltage and for turning the lamp on and off to minimize energy waste. The ballast may also include circuitry for dimming the lamp by varying the frequency or phase of the alternating current.

How do you know if a light is too close to a plant?

It’s important to remember that we are not looking at the plant itself, we are looking at the light. If it is shining directly onto the leaves, or even the top of the plant, then the light is too close and you should move the light away. If the plant looks a little wilted and the leaves are turning yellow, then you may need to adjust your light to make sure that the light is not shining directly on the leaves.

When is the right distance the most important for a 1000w HPS?

You want to pay the most attention to this during the flowering stage. This type of light is highly recommended for this stage in the growing process. As a matter of fact, many people only use this light for this stage in the growing process. Sometimes after applying a MH grow light beforehand.

Can you have too much light in a cannabis grow tent?

Yes you can, and the plants will show signs of this. This is why it is very important to keep not only the right amount of lights, but the right distance between them and the plants.

Different hanging distances are recommended for various grow lights. We have concluded that the ideal distance from plants for 1000w HPS should be around 20 to 36 inches.

Whenever you purchase a new grow light, you can start with the recommended hanging distance and monitor your plants closely. You should back off the lights if you notice any bleaching of leaves. If you however notice your plants are fine with the distance, you can bring them a little closer so they can get optimal lights for their growth.

In all this, always keep a close eye on your plants’ response anytime you are using a new grow light on your plants. You should be able to obtain the appropriate hanging heights for your grow lights. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of, Inc. or its affiliates.

It’s ok I start to grow my seed under 1000w HPS?

Im starting my seed under 1000w hps, tune it down to 600w mode
Keeping it in the maximum height in my grow tent.
It is too much light for seedlings?

  • Join Date: Nov 2017
  • Posts: 647

Should be fine. leave it as far away and low powered as possible until you see stretching start. Then you can slowly start working it back down to the preferred height.


  • Join Date: Nov 2016
  • Posts: 499

It is fine putting a seedling or clone under a HID light, but you will be wasting a lot of energy doing so. You will also need to hang the light fairly high to prevent photodamage. As young plants cannot photosynthesis at high levels in early stages of their life. Although some strains are more tolerant than others, this is just a result of efficient photoprotection systems. As such doing so slows the whole process down as the plant trys to survive through the stress from light.

If you have a lux meter, shoot for around at least 5000 lux, no more than 20,000. Preferably though, i would just put the girls under some CFLs save some money from the wasted power.

Check Out Our Social Media Channels For More Resources:

How Many Watts Do You Need to Grow Indoors?

Do you need 1000W to grow indoors? Not with LED Habitats Grow Lights

A lot of people believe that you need a 1000 watt artificial light to grow hemp indoors. The reality is, you can successfully grow medicinal herbs with far less wattage, saving you money on your electricity bill while growing healthier plants. So, how much wattage do you really need to grow indoors?

Let’s take a look at this short day plants-growing myth, and how you can grow indoors with eco-friendly (and wallet-friendly) LED grow lights.

Where the myth that you need 1000W to grow hemp comes from

The idea that we need 1000 watts to grow hemp comes from the days when it was common to use High Pressure Sodium (HPS) lights to grow anything indoors. At the time, HPS lights were the only decent artificial light source on the market, and a 1000 watt light was necessary for a sufficient photosynthetic light spectrum.

The main problem with HPS lights (and other high-intensity discharge / HID lights) is that they end up wasting up to 60% of the energy they consume solely on heat output. In other words, if you’re using a 1000W HPS light to grow indoors, only 400W of that energy is being used for plant growth – the other 600W is being wasted, draining money from your pocket.

Those 400W are also giving you a fairly narrow grow light spectrum, so your plants end up not getting the amount of proper light they need.

How much wattage do you need to grow indoors?

The simple answer is: it’s not really about wattage.

Wattage is a measurement of electricity consumption, and while it’s helpful to know how much wattage your grow light uses (so you can make a more economical, energy-saving choice) it actually has nothing to do with the amount of energy your plants need to grow.

Instead of looking at how much wattage a grow light uses, it’s far more important to understand the grow light spectrum, which is measured in micromoles (?mol). You need anywhere from 180 to 1300 ?mol to grow plants with grow lights, depending on how light hungry your plants are. The Cannabaceae family of plants are on the higher end of the spectrum: they need 800 ?mol to grow up to 85% of their natural potential, or 1300 ?mol to grow to 100% of their natural potential. Kitchen herbs,salads and other leave plants on the other hand only need 180-380 ?mol.

You can use a PAR meter to determine your grow light’s intensity in ?mol for light spectrum between 400-700 nanometers (nm) – in other words, for any light spectrum that’s suitable for growing plants.

Can you use too much light to grow indoors?

Yes. Much like a human sunburn, your plants can burn or bleach if you use too much light.

More wattage may mean more light output, but it also means more heat output, which can lead to burned plants. If your grow light has an output that’s higher than 1300 ?mol, your plants can go into what’s called photoinhibition, when plants start spending more energy on getting rid of excess light rather than growing to their fullest potential. As a result, you’ll be left with wilted, brown leaves and dying plants.