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Help with using a Fluorescent light.

Posted by DetroitChili none (My Page) on
Wed, Feb 9, 11 at 11:25

Hi, I'm going to try starting some various chili plants out from seeds this year. I have already purchased a Burpee ultimate growing system. I'm planning on setting this up near a window and using a F15T8/AR/FS Fluorescent plant aquarium terrarium tube light bulb. The light if from an old fish tank set up that is not in use. My question is can this light work with seedlings or do I purchase another type of light for the sprouts?

I'm looking forward from hearing from you.

Follow-Up Postings:

RE: Help with using a Fluorescent light.

I am getting ready to TRY to start pepper seed. I will be using bottom heat and T8 or T12 4 ft shop light. I have trouble with germination and the plants being too skinny and tall if I dont give them atleast one shop light about an inch above the plants. I have never used bottom heat before but I hope it will speed up germination.

I have three starting benches, one with one T12, 80 watts, one with two T12, 160 watts and one with two T8, with 128 watts. I would expect you will need a lot of help from the window, or you are starting only a few seeds. Larry

RE: Help with using a Fluorescent light.

Just a reminder...most pepper seeds like about 85 degrees bottom heat and some varieties need more time to germinate than others, so don't be discouraged if some sprout right away and others don't. Your patience will reward you. You will definitely need to place the seedlings as close to your lights as possible as soon as they sprout, so keep each variety in its own container/cell pack to make the task easier.

RE:RE: Help with using a Fluorescent light.

Sorry, I got off track. Your aquarium light should work but how big is the tank and is it just one tube? If it's just one, then you may have to add a second or the seedlings on the edges may get leggy. Any Flo light set-up would work for starting your plants. I use 8 compact flo bulbs(in a reflector hood)for mine and they work fine.

RE: Help with using a Fluorescent light.

@noinwi - Thanks for the quick response. I only have the one light but it is also next to a south facing window. It is very warm. I'm sure it will work out and grow fast.

RE: Help with using a Fluorescent light.

Normally you want seedlings around 1 1/2" to 2" from a cooler running fluorescent bulb, at the most 3" if you want more solid growth. But there's a problem with T8 bulbs, they usually get too hot and will sizzle up anything close to it, leaves, stems etc. Some T8 bulbs run a little hotter, whereas some T8 bulbs run a tiny bit cooler so they are not all the same.

T8 bulbs are good in multiples because you can place them further away from the plant canopy that way, whereas T12 bulbs can have plants resting right up against them with no harm whatsoever.

If they are genuinely getting direct sunshine from that window then a single 4ft bulb should work as a supplementary. But with no window you would need an absolute minimum of 2 bulbs, but preferably 4 bulbs. 4 bulbs make a very big difference -vs- just two of them by the way. Dual 4ft shoplights can be had for as low as $10 at Home Depot, Lowes, Walmart and Menards. And Two GE Kitchen and Bath bulbs will run you another $5. So for around $30-$35 plus tax anyone can have themselves a perfect beginner light setup. (TWO shoplight fixtures + FOUR T12 GE K&B bulbs = only 160watts and over 13,000 lumens btw)

Just a few things to keep in mind...

Oh yea, check out the fluorescent bulb grow comparison in the link below:

Here is a link that might be useful: fluorescent bulb grow comparison

RE: Help with using a Fluorescent light.

I like to use four foot shoplights that hold two tubes per fixture. I use two fixtures per shelf for most house plants, but for vegetable plants, you might want to use three or four. I prefer four foot tubes because the light output falls drastically on the last six inches of the tube. This means that with a twenty four inch tube only a twelve inch space in the center of the tube gives full light. on a four foot tube you have full light for a 36 inch space. Three times the light with only twice the wattage. actually this dropoff of light is quite useful since you can use the end area for plants that need less light, for example, begonias. My shelves are two feet wide by fout feet long. For garden plants, you will want to keep the lights as close to the tops of the plants as possible without actually touching. Be sure that you allow some method of raising the lights as the plants grow. Tomato plants started indoors in early April can easily reach eighteen inches tall by planting out time in mid may in our area. For light,I prefer to use a mixture of day light and soft white tubes. Daylight tubes are very high in blue light but weak in red, while soft white are rich in red, but deficient in blue. Don't waste your money on the pink "plant light" tubes such as are often used in aquariums. They don't give enough of any color light to be useful for bedding plants. If you buy "plant light" tubes use the Wide Spectrum kind. They give off a lot more light and the white color won't distort the colors of your plants. A sickly yellowish plant won't look a healthy dark green.
A reflective background will increase the light intensity in your growing area. The best reflector is flat white paint. Dont be fooled by ads for metallic foil or mylar. Foil reflects 85% of the light that hits it while white paint reflects about 95%. I personally stop by my local discount store and buy snow white (not beige or cream)shower curtain liners and hang them on three sides of my light stands. This increases the ambient light in the growing area by about 50%. I also place a small (5") desk fan on or near each shelf blowing on the ballast and tubes. this keeps the temperature in the growing area more even by distributing the excess heat throughout the room and thus reduces the load on your furnace.
My light stands are made of 1" pvc pipe. Plans are available for free on the internet. I do not glue the pipes together. they have stood up for three years of heavy use so far and can be easily broken down for storage when not needed.

RE: Help with using a Fluorescent light.

Emmitst if you take a look at that link i posted in the post above yours then you may end up rethinking some of the stuff you've heard about bulbs.

Apparently some are very hit or miss despite what they claim on their labels. There is a fairly easy way to tell what sort of blues/reds/greens/yellows a fluorescent bulb is putting out, take a look at this thread to see how you can do it:

Here is a link that might be useful: Easy spectrascope

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