Newbie here saying hello

[GpsFrontier]

Hello newhydro16,
I would use florescent lights myself. I don't know what your spacing is or how much coverage area your trying to get out of the two 45 watt led lights. But each 45 watt light probably wont cover more than one sq foot each. Have a look at this video Low Watt LEDs vs T5 grow lights. For lettuce you'll need a minimum of about 35 watts of LED lighting per sq foot. However with florescent lighting you only need about 27 watts of light per sq foot. That's less wattage for florescent lighting. Four 4 foot T5 bulbs is enough to easily cover a 2x4 foot space and plenty to grow lettuce. each 4 foot T5 bulb is 54 watts x 4= 216 watts total. 216 watts divided by 8 sq ft =27 watts per sq foot.

With that said not all LED's are manufactured the same. Some will preform better, and others worse. To understand why you first need to understand wavelengths of light. Wavelengths of light are different than spectrum of light. Wavelengths are specific, and spectrum's are a range. Red and blue are spectrum's (ranges) of light that are made up of specific wavelengths. Think of it like a radio. FM radio is a range/spectrum of individual wavelengths. Radio stations broadcast on a specific wavelength, and there are a lot of individual specific wavelengths within the spectrum of FM radio. The same holds true for light. You can also think of it like shades of light. While Red is a color there are hundreds of shades of red. Red is the spectrum, but each specific shade of red is a wavelength within the spectrum.

You can't tell how many individual wavelengths of light there are in a specific color. You know you see red or blue, but you can't tell how many specific wavelengths are present in what your looking at, nor can the human eye tell how strong those wavelengths that are there are. So in other words while one red LED light may look just like another, they can be vastly different in actual light output. This is why you really have to research the manufacture of the LED lights to find out if not only do they know what they are doing in manufacturing them, but if they do growth rate, as well as growth quality testing comparisons. Otherwise it's just a crap shoot.

You should also know that each specific wavelength of light affects plant growth differently. Even though it's not commonly known, plants even use wavelengths from the green spectrum of light to build structure. Each individual wavelength of light is used differently by the plant, so they need a good range of wavelengths to grow properly. Many LED lights result in abnormal growth because they don't provide enough range of wavelengths. Again this is why you really need to research the manufactures of the LED lights.

P,S.
You'll be able to tell if your plants aren't getting enough light by looking at the growth. If their getting long and leggy, their not getting enough light. If their growing abnormally small and thin leaves their not getting enough light. If the stems aren't getting thicker and their continuing to grow tall like their going to fall over because the stems can't support the weight, their not getting enough light. Being able to tell if their getting enough range in the wavelengths of light is harder to tell since many of the symptoms can be a result of nutrient balance and/or pH as well.

[newhydro16]

Both are 45 watts each seem to cover my dwc more then enough.
All I can tell from description is 660 wave lengths, spectrum ratio, red blue = 2.25.1
I admit, no clue here.
Thanks for your help, and patience with me.
ph seems to be holding about6.0

[GpsFrontier]

Hello newhydro16,
LED's have a very short usable distance for plant photosynthesis. The light intensity plants need for photosynthesis is very different than humans need to see with. Sounds like a pretty narrow wavelength range with one specific wavelength (660 nm). The wavelength range for the red spectrum is from about 610 nm to 740 nm, and the blue spectrum ranges from about 425 nm to 520 nm. The green spectrum ranges from 520 nm to 565 nm.

What Wavelength Goes With a Color?
Electromagnetic spectrum

But as long as you already have them see what happens. Even if the LED's give good growth quality, two 45 watt lights won't be able to grow many plants. If you plan to grow much lettuce you'll need more coverage area and will be much cheaper using florescent lights. If you do get good growth quality from those LED's, they would be good for starting seedlings in a prorogation system. You wouldn't need more than 2 or 3 sq feet for a prorogation system to start seedlings. That way you can rotate new plants into the main system as you harvest. That not only shortens the time the plants need to grow in the main system by 2-4 weeks and makes it much more productive. But also separates the seedlings from the larger plants because the nutrient strength for seedlings is much lower than for larger plants. If you plan to have a continual supply of lettuce you'll want to start seedlings in a prorogation system and rotate plants anyway.

[newhydro16]

Thanks GPS,
sounds like a good idea

[shillamus]

I bought a big bag of black seeded simpson lettuce seeds from the hardware store.

They were easy to sprout in grow block on a tray and took root in severe hot weather in my outdoor system.. But the lettuce was really leafy

I want to find some real good iceberg or romaine seeds.

newbie.. GPS has said many times here.. the only way to learn is try
I am looking forward to my second year of growing

I believe hydropnic gardening will become more prevalent with climate change

[newhydro16]

Yes, from seed, Buttercrunch.
I had them in soil until I decided to try my hand at hydroponics, so I carefully pulled them and rinsed them. Have to admit, I have spent a lot more then I thought I would on getting going.
Water temp is a little low I have a heater ordered, and, GPS, I ordered a two bulb t5 light.

[GpsFrontier]

Hello newhydro16,
Growing your own produce hydroponically is all about being economical. Pot growers make $1,000 to $2,000 a pound for their product so they don't have to care about being economical. But if your going to grow produce, you need to think about being economical, everything from the choice of hydroponic system and how you design it, to the type of growing media, to how you test pH, the nutrients and pH adjusters you use, and especially your lighting. It's all about maximizing your resources, and minimizing your costs.

But don't be discouraged, you learn by doing, and you'll learn more about how to be economical as you go as well. Almost every new hydroponic gardener winds up spending much more than they need in the beginning. Most Hydroponic shop salespeople don't help you be economical much either. They aren't in the business of helping you be economical, their in the business of selling as much product as they can. So they try and convince people you have to have the best of everything. Some of the sales people don't even know much about hydroponics to begin with and only work there. I'm not saying that hydroponic shops and/or all the people that work there are crooks. But they do have an agenda, and that is to sell products so they can make money and stay in business.

So it takes time to learn what you don't actually need and what you do need, as well as sourcing out economical products, and how you can repurpose things to build hydroponic systems with. The first lesson in being economical is only buy what you have to at a hydroponic supply shop. General that means only nutrients, pH adjusters, pH drops, possibly growing media depending on what type your using, and only if you have to and your not using florescent lights artificial lighting. Manufactures typically feel if you add the word "hydroponics" to the product, it's automatically worth twice as much. Even when you have to buy from a hydro shop, when it comes to nutrients and artificial lighting there's often a big difference in price depending on where you buy from. Just because it's expensive doesn't make it better. It's all about sourcing out the right vendors.

The optimum water temperature for plants is between 68 and 75 degrees Fahrenheit. That's just the optimum temperatures, you can easily be a little above or below that without any problem. if the water temps start regularly going below 60, and/or above 82-84 you'll want to start worrying about it. Lettuce is a cool weather plant, so you'll want your water temps to be on the low end (under 80).

I don't know where you ordered your heater or lights from, but a inexpensive fish tank heater you can get at any pet supply place and can get for $10-$20 is all you need. You can even get them at Wal-mart in their pet supply section. T5 lights you can get at any hardware store like Home Depot and Lowe's for about $35-$40 for a 4 foot twin bulb fixture with the bulbs included.

P,S.
One twin bulb T5 wont cover more than a one foot wide area. The maximum coverage area would be 1 foot wide by the length of the bulb.

[shillamus]

Originally Posted by GpsFrontier

Hello newhydro16,
LED's have a very short usable distance for plant photosynthesis. The light intensity plants need for photosynthesis is very different than humans need to see with. Sounds like a pretty narrow wavelength range with one specific wavelength (660 nm). The wavelength range for the red spectrum is from about 610 nm to 740 nm, and the blue spectrum ranges from about 425 nm to 520 nm. The green spectrum ranges from 520 nm to 565 nm.

What Wavelength Goes With a Color?
Electromagnetic spectrum

But as long as you already have them see what happens. Even if the LED's give good growth quality, two 45 watt lights won't be able to grow many plants. If you plan to grow much lettuce you'll need more coverage area and will be much cheaper using florescent lights. If you do get good growth quality from those LED's, they would be good for starting seedlings in a prorogation system. You wouldn't need more than 2 or 3 sq feet for a prorogation system to start seedlings. That way you can rotate new plants into the main system as you harvest. That not only shortens the time the plants need to grow in the main system by 2-4 weeks and makes it much more productive. But also separates the seedlings from the larger plants because the nutrient strength for seedlings is much lower than for larger plants. If you plan to have a continual supply of lettuce you'll want to start seedlings in a prorogation system and rotate plants anyway.

GPS.. I was curious.. I know there are 200W CFL's out there.. are they effective? Flourescents have a better spectrum?

[GpsFrontier]

Hello shillamus,
It depends on what your growing with it and how you have things set up. CFL's are the same thing as T5 florescent lights, except their more compact. hence the term CFL (compact florescent light). CFL's have the ballast in the base of the bulb, straight tube florescent lights have the ballast in the light fixture.

Weather their compact or straight tube, all florescent lights have the same issue. The usable light range is very short. The luman drop off rate goes way up beyond 2 feet from the bulb. In other words at 1 foot from the bulb your getting about 85% of the usable lumins/par to the plant foliage, at 2 feet your getting more like 60%, at 3 feet from the bulb your only getting about 25% of the lumans/par reaching the plant, at 4 your getting basically no usable light. Same goes for LED lighting.

While a 200 watt CFL will concentrate more lumans/par in one area, the coverage area is smaller. As an example four, 4 foot T5 bulbs equal 216 watts and will cover 8 sq feet of area. While a 200 watt CFL will only really cover about 4 sq feet. So the wattage is about the same but the coverage area is cut in half. You don't need 200 watts per 4 sq feet to grow lettuce. It would grow faster because of the higher light intensity. but not really worth all the extra electricity. You would be better off with the larger coverage area and growing more plants.

With that said fruiting plants take about twice as much light intensity (par/lumans) to support the fruit. While it is possible to grow fruiting plants with florescent lighting, it's not cost effective. Watt per watt your much better off using HID lighting to grow fruiting plants, especially large ones like tomatoes.

As for spectrum of florescent lighting, higher wattage doesn't mean better spectrum. It means higher light intensity (output). Unless the manufacture is selling their lights in the hydroponics industry they don't usually provide a wavelength (spectrum) chart for comparison. It's not that florescent bulbs sold in hydroponics shops are necessarily better than standard bulbs and that's why they provide the charts. Manufactures selling their florescent bulbs for household and shop lighting don't need a wavelength chart because people buying them for that reason aren't comparing wavelengths. They compere the color of the disable light by the K value. They typically range from 2400K to 6500K. The lower the K value the more of the red spectrum the light puts out, the higher the K value the more of the blue spectrum there is.

[newhydro16]

Thanks again GPS told you Id be a pain in the butt

[GpsFrontier]

Hello newhydro16,
While helping people is time consuming, I don't mind trying to help people who want/need the help. The way I look at it is if I help you be successful you can help someone else be successful later. That's what makes the world go around.