Types of Bulbs for Indoor Cannabis Grows

Types of Bulbs for Indoor Cannabis Grows; today we’re going to talk about  the different classes and types of bulbs that you can get on the market, what each one is for and how efficient they are (we tried them all on our own plants). If you’re not sure what bulb to use or if you want to know why certain bulbs are twice the price of others, take a look at this article and you’ll understand.

Within the world of grow lights you can find energy-efficient bulbs and discharge lamps. Which is which? Well, they differ in various things, mainly that discharge lamps need a ballast and energy-efficient bulbs can be connected straight into the wall.

And of course, within those two types you can find growth bulbs, flowering bulbs and mixed bulbs. Growth lights give a light spectrum that’s kind of blueish-white, simulating the strong and persistent sunlight of spring which stimulates growth.

Flowering bulbs have yellow-red colors, which simulate the fall time which is when outdoor plants begin flowering, which therefore stimulates flowering in your plants.

Discharge lamps also have mixed lights, which can be used for both growth and flowering stages. These kinds of lights are the most common ones found in indoor beginner crops.

After all of that you’ll also need to pick the wattage that you’ll need; this is chosen depending on the space you have available for your crop and the amount of yield that you’re looking for. We’re going to make a list of all kinds of bulbs, model by model, so you can know what you’re buying and what type you need for your grow.

Energy-efficient bulbs:

These bulbs are the ones that look like normal house lights except they’re much bigger. They’re perfect for using in small spaces as they hardly heat up and it’s easy to keep your grow’s parameters in check.

They don’t use a lot of power and they’re quite easy to install, all you need is a reflector with a light socket and a plug straight to the wall. Bring it as close as you can to your plants, making sure that it covers the entire grow area. Growth lights are perfect for putting on top of greenhouses or propagators when you’re rooting clones or for maintaining mother plants, as well as germinating and of course normal plants in the growth phase. You can also use it to help HPS lamps out when it’s too hot in the summer; you can switch out three of the six HPS lamps with energy-efficient bulbs and therefore lower the temperature in your grow considerably.

These bulbs are different when used for flowering however, they have a slight yellow color to them, although personally I don’t think they’re powerful enough for a healthy flowering period but you can use them like we said before, as a supplement for a hotter lamp. Some people don’t have any other options as their grows tend to heat up too much, so they use these bulbs and have to wait a couple more weeks as well as getting a lower yield.

They’re available in various wattages for all sorts of spaces. 105W bulbs are good for small greenhouses, around 60x60cm. 125W bulbs should be used for 80x80cm. 200W can be used for 1x1m spaces and 250W can be used for 1.2×1.2m grow tents.

Discharge Lamps:

These bulbs are full of heavy metal gases, like High Pressure Sodium (HPS) or Metal-Halide (MH) which are the most common discharge bulbs. Within each kind there are different wattages and brands. Like we said before, the wattage depends on the space that you want to light.

We recommend 250w for 80x80cm, 400w for 1x1m, and 600w for 1.2×1.2 at about 3m off the ground; these bulbs are extremely powerful.

Within these different wattages you can find different brands which, even if you don’t believe it, really do have a lot of differences. Here’s a list of them and my personal point of view on how useful each one is:

Argolite Gro & Flo Mixed Bulb:

This is the most used bulb here in Spain thanks to its price; it’s one of the cheapest ones on the market right now. You can get a decent yield with these bulbs, and they give off a decent luminosity, although after a couple of harvests the intensity of the bulb tends to decrease quite rapidly. You can’t see it with the naked eye, but if you have a light meter you’ll be able to tell. Almost everyone’s first bulb was the Argolite Gro & Flo. It’s a good idea if you have no other choice, but for just a little extra money you can get much better lights. Available in 100W, 250W, 400W, 600W and 1000W.

Sylvania Grolux Mixed Bulb:

This bulb is higher quality than the Argolite one. It has a more yellowish color and if you use your light meter to check, you can easily tell that the light is more intense straight away and it will last for much longer. Hardly any intensity is lost in between harvests, and you can get up to four harvests with this bulb before it loses too much intensity, although it will keep working for much longer. Plants flower really nicely under this light. Available in 400w and 600w.

Philips Green Power Mixed Bulb:

Philips is probably the master of lights at this stage, and they have the perfect mixed bulb for your grows. This bulb can be used in both growth and flowering, rewarding your plants with a compact growth and exuberant flowering period. I think that the secret to these bulbs is the intensity of the light because when you go to check on your grow the light will practically blind you as soon as you enter the room. This bulb is the perfect choice if you want to get the most out of your plants without having to change the bulb as it works perfectly in growth and flowering, and that way you don’t have to mess about and try get the light out of the cooltube, which can be annoying.

Argolite MH Growth Bulb:

 Metal-halide bulbs that have a powerful white light which will make your plants grow as compact as they possibly can. If you use this bulb your plants will have short, strong branches that will be more than ready for flowering. When you’re growing in small spaces, the ideal thing is to use these kinds of lights as they will make your plants stretch a lot less than mixed lights. They also let off a lot of heat, so don’t let your plants get too close to the bulb and keep an eye on the temperature with a thermos hygrometer; place it at the top of the closest plant to the bulb and make sure the temperature is not over 25ºC. If it is you can move the bulb further away, they will still grow nice and strong. If you need to move it over a meter away from your plants you might have ventilation issues in your grow. Available in 250w, 400w and 600w.

Philips HPI-T Growth Bulb:

This nice blue-white light will have your plants basking in the spring sun; the plants will grow nice and compact as this kind of light won’t induce them to flower or to even contemplate it. This light is another MH bulb and it can only be used in the growth period; it’s perfect for mother plants from which you want to get various clones every now and then as this light will help it sprout many new branches and they won’t stretch out too far. With this bulb, the most intense and penetrating light can reach even the lowest leaves. Available in 250w, 400w and 1000w. Strangely, there’s no 600w model available.

So there you have it, here’s a list of the best bulbs that you can get on our webpage. Use this list to check out which ones you think are good for your indoor grow. Sometimes those extra 10 quid are nothing compared to the results you can get over three or four harvests. Happy growing!