Hydroponic Tomatoes

[Cole_Robbie]

Blue light causes cumulative irreversible degradation of human eyesight.

From UV rays, right? Metal halide bulbs are considered blue, but they have a coating that is supposed to absorb the UV. Does that sort of coating or filtering lens not exist for LEDs?

[Urbanfarmer]

Hi all......I found this forum 3 weeks ago and now that I'm registered....here we go. Hydroponic tomato growing is the first thing that caught my eye, because that's a big part of what we do. To be straight up, "we" is HydroSystems, a company dedicated to hydroponic vegetable production at the homeowner level. I'm not going to use this forum to plug our products. But we do know what we're doing. So, my passion is to shout out......

"Producing gourmet-quality hydroponic tomatoes is actually quite simple", certainly much less difficult than is widely thought. You need a good growing platform, good nutrients, good light, and good seed. Well, good water helps too. If you are weak on any one part, you will do poorly. If all your ducks are in a row, you will grow tomatoes that will compete head-to-head with the best tomatoes you've ever eaten. No exaggeration. Heirlooms or hybrids.....doesn't matter.

Top shelf hydroponic vegetable production is real. Stick with it.....and believe it! Contrary to urban myth, it's not rocket science. OK, that's all I wanted to say.

[Redbaron]

Welcome UrbanFarmer

[Elagrow]

Studies made many year ago on pigments extracted from plant tissue revealed a series of spectral wavelength absorption peaks. The most prominent of these are chlorophyll A peaks at 430 and 662 nanometers, and cholorophyll B peaks at 453 and 642 nanometers. The 453 and 662 nanometer peaks are the greatest and it is now believed that most or possibly all plants will thrive under light with only these two wavelengths. Keep in mind that these tests were made in a laboratory on isolated pigments. We may someday discover that living plant tissue has other preferences.

First off, This is very interesting, do normal lights hit both sets of nanometers that plants use? or would it require multiple lights to handle such a spectrum variety?

You also mentioned that you build your own LED's, do you have a link to the manufacturer of the filaments and ballasts for that? or for a retailer even? I would like to dabble into that abit and experiment in LED's.

I am also aware of the dmg that blue light can do to your eye's, I was a professional welder for sometime, and the concept is the same I think, but I think welding glass might be abit to strong for any light system use for plants. Do you have any suggestions on eye protection for a blue light system?


Also, can I ask what you retired from?

[Elagrow]

Originally Posted by Cole_Robbie

Blue light causes cumulative irreversible degradation of human eyesight.

From UV rays, right? Metal halide bulbs are considered blue, but they have a coating that is supposed to absorb the UV. Does that sort of coating or filtering lens not exist for LEDs?

I dont think MH bulbs produce enough blue light to hurt the eye's that bad. he was saying high output of blue light can be bad for your eye's.

"Producing gourmet-quality hydroponic tomatoes is actually quite simple", certainly much less difficult than is widely thought. You need a good growing platform, good nutrients, good light, and good seed. Well, good water helps too. If you are weak on any one part, you will do poorly. If all your ducks are in a row, you will grow tomatoes that will compete head-to-head with the best tomatoes you've ever eaten. No exaggeration. Heirlooms or hybrids.....doesn't matter.

I know it is possible and not that hard to do after I tasted my first set of Bitonto's. They were very good, and I cant wait for the rest of them to ripen to have a good salad with them.

[Sequim]

From UV rays, right? Metal halide bulbs are considered blue, but they have a coating that is supposed to absorb the UV. Does that sort of coating or filtering lens not exist for LEDs?

Well, UV is damaging of course but I was referring to longer wavelength blue light; specifically the 453 nanometer royal blue that is so perfect for plant growth.

There are UV-emitting LEDs, but unlike gas discharge lighting there is no UV present in light from royal blue and deep red LEDs. LED's tend to be monochromatic. They emit only one narrow band wavelength so there are no other unwanted wavelengths to filter out.

[Sequim]

Hello Urban Farmer

Speaking for myself, I hope you can find a way to share some of your expertise within the forum rules. I have much more to learn about hydroponics and specifically tomatoes and would appreciate an information source so near at hand.


Pete

[Sequim]

First off, This is very interesting, do normal lights hit both sets of nanometers that plants use? or would it require multiple lights to handle such a spectrum variety?

HPS lamps do not present the wavelengths considered optimum for plant growth. Instead they take the brute force approach with high energy in other wavelengths. Remember that plants are very resourceful about this. They contain pigments that convert light of non-optimal wavelength to the wavelengths needed for photosynthesis. The down side of this is the conversion inefficiency; much of the provided light energy is wasted in the conversion. Another downside is the conversion direction; it is always toward a longer wavelength. The accessory pigments cannot convert to the blue chlorophyll peaks.

Here is a link to a HPS spectrum chart. There is absolutely no energy at the four chlorophyll peaks of 430, 453, 642, and 662 nanometers. Literally all of the plant's basic needs must be converted from other wavelengths.

http://en.wikipedia.org/wiki/File:Hi...p_Spectrum.jpg


This might be a good time for a minor disclaimer. The 430, 453, 642, and 662 nanometer chlorophyll peaks are generally believed to be acceptably accurate until something better comes along. It is quite possible that researchers will discover variants at some future time.

There is even older research from 1969 that somewhat agrees with today's beliefs, but it was performed with more primitive equipment and should be considered less accurate. On the other hand it was performed on living plant tissue instead of extracted pigments. Who really knows?

Regarding eye protection, I have no recommendations. I use ordinary blue-blocker sun glasses, but also flood the room with white LED lighting on entry to constrict my pupils and reduce the entry of blue light. I also turn off the LED's before doing any serious work with the plants.

Also, can I ask what you retired from?

I usually answer that I am a retired avocado orchardist. This is true; my small orchard of slightly less than 1,000 trees produced around 60,000 pounds each year during the 26 years that I owned it. But my real day job was electronic engineer. This gives me a slight edge when it comes to building my own LED luminaires.

Finally, regarding your interest in experimenting with LED's, I will prepare a post tomorrow with a little information about the devices I've selected. LED's are very simple devices that are very easy to use as long as you obey a few simple rules.


Pete

[Cole_Robbie]

HPS lamps do not present the wavelengths considered optimum for plant growth. Instead they take the brute force approach with high energy in other wavelengths.

HPS slashes the Gordian Knot indeed. I don't know that LEDs have untied it yet, though.

If you could show actual plant, side-by-side results with your led lights outperforming an hid light, then a lot of people would be very interested in that, myself included. Everyone agrees that day is coming, but I still haven't seen it yet.

[Crandrew]

Here we go

http://www.lighting.co.uk/news/mit-c...627537.article

A group of researchers in the US have unveiled an LED which emits more light energy than it consumes in electrical energy.
Researchers from the Massachusetts Institute of Technology (MIT) unveiled the LED, which has a conventional efficiency of greater than 200 per cent.
This means that unlike traditional halogen lamps and newer LEDs, instead of producing heat this LED will instead cool its surroundings.
Lead researcher, Parthiban Santhanam of MIT, said: “The most counterintuitive aspect of this result is that we don’t typically think of light as being a form of heat. Usually we ignore the entropy and think of light as work.”
The possibility of such a device was first predicted in 1957, but a practical version was seemingly impossible to create until now.
Jukka Tulkki of Aalto University in Finland, told physicsworld.com: “I think this is a historically important breakthrough…that could eventually lead to more useful and technologically relevant applications.”
Alongside energy-efficient lighting other potential applications of the LED could include cryogenic refrigeration.

[Cole_Robbie]

That is really neat. I would love to have a light with built-in air conditioning.

[Keger]

Originally Posted by Urbanfarmer

Hi all......I found this forum 3 weeks ago and now that I'm registered....here we go. Hydroponic tomato growing is the first thing that caught my eye, because that's a big part of what we do. To be straight up, "we" is HydroSystems, a company dedicated to hydroponic vegetable production at the homeowner level. I'm not going to use this forum to plug our products. But we do know what we're doing. So, my passion is to shout out......

"Producing gourmet-quality hydroponic tomatoes is actually quite simple", certainly much less difficult than is widely thought. You need a good growing platform, good nutrients, good light, and good seed. Well, good water helps too. If you are weak on any one part, you will do poorly. If all your ducks are in a row, you will grow tomatoes that will compete head-to-head with the best tomatoes you've ever eaten. No exaggeration. Heirlooms or hybrids.....doesn't matter.

Top shelf hydroponic vegetable production is real. Stick with it.....and believe it! Contrary to urban myth, it's not rocket science. OK, that's all I wanted to say.

Welcome!

I've talked to you on the phone a few times. Looking forward to adding your systems to what I do. It's great stuff.

This place is really cool!

Enjoy!

[Sequim]

If you could show actual plant, side-by-side results with your led lights outperforming an hid light, then a lot of people would be very interested in that, myself included. Everyone agrees that day is coming, but I still haven't seen it yet.

I haven't seen it yet either, but I'll keep tinkering until something looks hopeful.

I think I'll leave it to someone with a financial incentive to present a comparative trial against HID. I'm too old to become a great crusader. But it would be nice to have a circle of colleagues with a strong interest in LED lighting. Good things usually come from collaboration.

Below are a few pictures of last year's model. It was only moderately successful, mostly because I used available 630 nanometer LED's for the red spectrum instead of 660 nm. My new version will provide 660 nm since these LED's are now fairly available.

First picture shows one segment. Its about 4 feet long and built on a length of 3/4" aluminum channel. The channel is to be press-fit onto a 20-foot length of 1/2" copper pipe suspended above the plant row.

Next is a closer view of part of the segment. The power supply shown is designed for outdoor LED signage and is adequate for one segment.

Finally a close up of a small portion of the segment. The LED's on the black thermal bases are red and the white ones are royal blue.

I believe my approach, the water-cooled thin strip lighting, will have the best chance of success with multiple plants grown in rows. I can pour at least five times the power into it compared to a compact air-cooled array with the same active area. Furthermore, water-cooling will keep the LED ★★★★★★★★ temperatures quite low so the LED's will operate more efficiently and last longer than those in the air-cooled array.

I've started work on my 2013 model which will be installed in my brand new indoor laboratory now under construction. This time I will make printed wiring boards for the LEDs to eliminate the tedious hand-wiring labor. It will all be ready for next winter with more room and better insulation than my present lab.

I'd be happy to provide all the details of this project to any interested tomatovillians; especially any who might want to try LED's themselves.


Pete

[Elagrow]

I'd be happy to provide all the details of this project to any interested tomatovillians; especially any who might want to try LED's themselves.

I am interested for sure, what is the rough cost for each segment?

[Sequim]

I don't do a very good job at keeping track of costs. The power supply itself is about $70. I'll let you know what I spend as the project moves along.


Pete