Thread: NFT Lettuce
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Old 01-10-2010, 10:23 PM
GpsFrontier GpsFrontier is offline
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From what I have read the cubes should not be touching the bottom of the gutter. I think I may have transplanted a bit early as the roots were not busting out of the cube.
Well ya, with a NFT system the roots should dangle in the flowing stream of nutrient solution. The dangling roots then wick up the nutrients to get the moisture they need. They also wick up the moisture into the growing medium, keeping it moist. But if the growing medium is touching this flow of solution it will become saturated depriving the root system of oxygen and or air. Some plants don't like keeping their feet wet as much as others. From what I understand Lettuces is a cool weather, low light, water loving plant. So they should not mind there feet being wet as much as others might, but you don't want to deprive them of oxygen/air either.

If you have the capability to adjust the water height, you can raise the height until it touches the bottoms of the growing medium and the roots start dangling down. But you would want to use a timer and set it to go on/off in intervals like a flood and drain system so that it's not running 24/7 as it does in the NFT. Then when they dangle down far enough you can convert back to the NFT system.

Quote:
If I leave the next batch in my high tech germinator pan an extra 2 to 3 weeks I would think the roots would be busting out. Again the only problem I see is that the roots still won't be dangling into the gutter flow and I will still have to top water them.
Well, you could possibility build something. I am thinking of something like using 2 stackable Tupperware containers, so one will fit inside the other but not go all the way down. Then cutting holes to fit your growing medium in one of them. Place the seeds in the growing medium, and the growing medium the holes. Then place the container with the growing medium inside the other one, and pour in just enough water to keep moist. This should hold the growing medium up so the roots can dangle out the bottom, and using the two containers should hold enough moisture so it wont dry out fast. It doesn't need to be Tupperware, but the idea is to have one container fit inside another so that it will hold the one with the growing medium in the air and provide the space underneath for the roots to dangle down. You could probably find something usable for this at the dollar store.

Quote:
I'm not sure how commercial growers solve this problem but finding out would answer the question.
I have not looked into that at this point. Although all commercial operations usually have greenhouses devoted to germinating seeds and complete control of that environment, including air temp, lighting, humidity, nutrient temp and delivery. This way they have a consent supply of plants the right size to replace the ones that were harvested, so there is virtually no down time and maximizing efficacy. To them building an automated spray system would be nothing.
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Last edited by GpsFrontier; 01-15-2010 at 04:51 AM.
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