Any part of the plant that is further away then 1-2 feet from the fluorescent grow lights is not getting an optimum amount of light, especially in the flowering stage when plants need a lot of light to produce buds.
With the new high output lights such as the T5 , fluorescent lights can be used until the plants are about 24 inches tall, which is just enough to grow a very short plant through to the flowering stage when you control your marijuana plant's growth through the vegetative stage.
A few years ago, growers usually only used fluorescent tube lighting as a supplemental light for cannabis plants, or for young seedlings and clones only.
For optimal results, for vegetative growth choose fluorescent light bulbs that are labeled either as "Cool White" or "Cool" colored (also labeled as "6500k" colored).
The other great thing about fluorescent lights is that they are usually relatively low powered and won't make a huge mark on your electricity bill.
However, you can use either type of lights during either stage and still get good results. People also use "Daylight" (5000K) bulbs with success.
Example of a ScrOG (Screen of Green) Grow Under a T5. Using a screen can be an effective way to create a flat, table-top shape to take the best advantage of T5 grow lights.
For flowering, choose bulbs that are "Warm White" or "Soft White" colored (usually labeled as "2500K" or "3000K").
There are many different levels of fluorescent grow lights including the T5, the T8 and the T12. I strongly suggest sticking with the T5 style of fluorescent grow lights for cannabis because they give off the most amount of light for the size, and are specifically designed to be able to support taller plants up to 24 inches.
Some growers even use fluroescent grow lights such as the T5 successfully to flower their plants (if the plants are kept short/small enough through growth control methods).
In recent years, we've seen the creation of new high-light-output versions of fluorescent grow lights which can actually be used through the entire vegetative stage.
The great thing about fluorescent grow lights is that they don't get very hot, and they can usually be kept 1-4 inches from the tops of the plants at all times without having to worry about burning your cannabis leaves or buds.
The biggest problem with fluorescent tubing is that the light that they give off is only useful for about a foot or so. That's why they're kept so close to your plants.
Training plants to grow very short will produce the best yields with T5 grow lights.
T5 grow lights should be kept as close as possible without burning your plants.
In general, I recommend changing to stronger grow lights like LEDs or HIDs for the flowering stage because they will usually give you double or more yields/watt of electricity. Unless you keep your plants very small, they will need more light to produce buds than a fluorescent light can usually produce. If you're in a dire situation where your plants have grown too big and you can't afford to get a different type of light, you can supplement your fluorescent tubes with additional light, for example you could supplement their light with a few CFL(compact fluorescent light) bulbs wherever you notice any "shadowy" areas. This is only a minor fix – the real fix is to grow very short plants or upgrade to a bigger light for the flowering stage.
If the temperature is under control they can be kept as close as an inch or two away.
If possible, opt for bulbs labeled as "High Output" (HO). This ensures that you're getting the most lumens (light) from your bulbs. But any T5 bulbs will work – hundreds of cannabis growers have the harvests to prove it!
Even stronger is the Apollo Horticulture 25-Watt bulb. This CFL bulb comes with a USA standard reflector and a 13ft power cord, perfect for setting up your grow space. The bulb is 6400K, but the brand recommends switching to a 2700K lamp during the flowering period.
T5s are the preferred fluorescent bulb of choice for more experienced growers. However, CFLs definitely work, too. Bear in mind that you’ll have to put up with a smaller yield with both types of fluorescent lighting.
Apollo Horticulture describes this bulb’s light as “warm and inviting”. It makes a pleasant and effective addition to your grow room.
LEDs (light-emitting diodes) are a favorite with growers because they last long, are super energy efficient, and emit very little heat. Still, they are powerful enough to produce high yields at the end.
For a relatively cheap price, the Hydrofarm FLC125W light provides excellent light quality. It can be placed both horizontally and vertically. The bulb provides 125-watt full-spectrum light in a warm tone.
2. Apollo Horticulture 250-Watt CFL Compact Fluorescent Grow Light Bulb System – 6400K.
There’s a lot to learn when you enter the world of marijuana growing. Newbies are confronted with a vast wealth of information and a steep learning curve. You need to learn about watering, feeding, pruning, and more. But before you even begin to grow your cannabis plants, you need a set-up.
With an 8ft power cord, this model also has the advantage of being water safe. The Durolux model should remain safe in damp conditions. Plus, there is an AAG Stucchi lampholder that prevents fire if the tubes become loose.
T5s, meanwhile, get their name from their tube shape and 5/8” diameter. T5 bulbs usually come in a set, where multiple tubes are placed side by side in a panel. As a result of this set-up, T5s provide more even light coverage. You’ll need to hang T5s from a fixture, but don’t worry, as they’re often very cool and won’t cause heat damage.
Growers recommend using this light in spaces that measure 3’x3’ or more. The reflector itself is 19” x 19” x 5”.
The brand offers a 1-year warranty on this product, and most customer reviews state that there have been no problems.
Please note that this bulb is not the best on the market. However, it is cheap and will do the job in the smallest grow tents.
So, there you have it. These are our five top picks for fluorescent lighting that will show some love to your cannabis plants. Make sure to do your research, though, as there are hundreds of fluorescent lamps available on the market.
Although this model doesn’t offer vertical positioning like the EnviroGro FLT24, it does offer two modes of light. Switching off some of the tubes allows for dimmer light that works better for times when you need it a little darker.
Another great thing about CFLs is that they can be positioned in innovative ways. Some people place them horizontally, while others dangle them vertically over the plants. Since they can fit into a small space, they’re pretty good for stealth growing.
1. Hydrofarm FLC125W Compact Warm Fluorescent Bulb.
Fluorescent lights are ideal for newbie growers who are experimenting with cultivation. While they are pretty useless for big growing operations, fluorescent bulbs work well in a small grow space.
Here are WayofLeaf’s top picks for fluorescent grow lamps. These should suit all budgets and grow spaces, no matter what you need.
HIDs (high-intensity discharge) are even more powerful, but they aren’t as energy-efficient and they use a lot of power. As such, they can give off quite a bit of heat. You may need to invest in a ventilation system to counteract this, leading to a higher cost.
There are two types of fluorescent lights: CFLs and T5. A CFL bulb has a twisted, coil-like shape, whereas T5s come in straight tubes.
This warm fluorescent bulb is designed for flowering plants, potentially negating the problem that often occurs with CFLs during the flowering stage. Most growers use this bulb with a reflector to ensure the best distribution of light.
Growers who have complex lighting set-ups using multiple lighting types often use fluorescent bulbs during the sprouting stage. Young plants respond well to these bulbs, but older plants sometimes require something more powerful. Sadly, you may get lower yields than if you used LEDs at a later stage.
3. EnviroGro FLT24 2-ft T5 Bulbs.
Establishing the space where you will grow your plants is crucial. Many strains can thrive outdoors, but most cultivators opt for indoor set-ups where they can control the temperature and light thoroughly. Since marijuana strains can be picky and sometimes require different conditions at different growth stages, indoor growing can provide you with the highest yield – if you do it right.
You can hang the lights overhead, vertically, or horizontally closer to the plants according to your preference. There is a 10ft grounded power cord to help you reach, and the powder-coated steel housing protects the T5 tubes.
There is much debate about what lighting type is the best for marijuana. Fluorescent lighting is a commonly used form of lighting, but you still need to learn which bulbs work best. In this guide, we cover the pros and cons of fluorescent lamps and explain where you can pick up the best fluorescent light for your grow space.
Compact Fluorescent Lamps (CFLs) have a coiled, twisted structure. These bulbs have a varying wattage, with some almost rivaling HIDs. Since CFLs are so common, you can find them at most household stores and even grocery stores. This is a blessing, but the downside is that you’ll need a separate socket for each CFL bulb.
Fluorescent Lamp Pros.
Fluorescent Lamp Cons.
While fluorescent lighting may work for small-time growers with a handful of plants, you will need to invest in an upgrade if you’re wanting to produce more marijuana. LEDs and HIDs are much better for getting a higher yield.
Dear Raymond, Yes, you can use a T5 fluorescent light to flower a pot plant. The benefits of using this type of lighting is the lack of heat that they generate. Because they’re not super-warm, you can place your plant tops within just a few inches of the light. The disadvantage of flowering under fluorescent lighting is the lack of light intensity and penetration. This makes the Screen of Green (ScrOG) method ideal as you can train the flowering tops to create a level canopy close enough to the light.
My recommendation, however, is to grow under High Intensity Discharge (HID) lighting such as High-Pressure Sodium (HPS) or (Metal Halide) systems. Although they run much hotter and use more electricity, they produce plenty of light for plants to thrive and build thicker flowers. If you’re interested in a bigger yield from increased light and can handle the added heat, HID lighting is ideal for indoor marijuana production.