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OChydro 01-09-2010 01:01 PM

NFT Lettuce
 
5 Attachment(s)
Lets talk NFT.

I recently started my bibb lettace in rockwool the same way as described in my dutch bucket squash thread. I have transplanted them into gutters. I went ahead and sprang for the CropKing gutters, all other parts are HomeDepot issue.

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. I read that if the cubes touch the bottom of the gutter they will stay too wet and I will get root rot. My plan is to reset them in the gutter, keep them off the bottom and wait for the roots to reach out for the gutter bottom. To keep the cubes from drying out I will just hand water them everyday or every other day to keep them moist. Since this is a small system, 1 gutter with 5 in the future, it won't be a problem.

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. I could always build one of the upspraying starter units which will develop the dangling roots I need but this is a pain, I want it to be simple. I'm not sure how commercial growers solve this problem but finding out would answer the question.

I am using the same reservior for my dutch bucket and NFT.

Luches 01-10-2010 11:22 AM

Hi OChydro,

Rockwool isn't exactly the best solution for lettuce in NFT, not for germination and for nursing neither. Actually roots tend to spread laterally in rockwool. I recommend special Lettuce cups, filled with a mix of 1 part Vermiculite and 3 parts of Perlite (both fine grade).

Also, (even if using rockwool) you can't transplant until the roots have grown long enough to reach the bottom of the gully! Just wait until they are at that stage, anything else is pointless (no offense).

PS: use adequate nutrient for lettuce and the very adequate concentration to grow your seedlings, (starting with PH corrected, low ppm, RO or even distilled water for germination and beyond) otherwise you have delayed root growth and loose "vital" time in the ongoing operation.

If you need pics of the lettuce cups, nutrient requirements or other hints, just call in again...

Cheers,
Luches

OChydro 01-10-2010 09:42 PM

Thanks for your reply. Pictures of the lettuce cups would be great but I'm not sure how I would use these in my gutters as they have 1 inch square holes, would they fit in my gutters? Please let me know.

Luches 01-10-2010 10:22 PM

Here is the cup with the size. Up to you if you use them and make them fit. As these are bigger than 1' it shouldn't be a problem.
Best is to have the cups in a shallow nursery with a continuous flow of water respectively week nutrient solution (like we have).

http://chiangmai-thailand.com/images/a/cup.jpg

Here they are in action in the gullies.

http://chiangmai-thailand.com/images/a/3sizes.jpg

GpsFrontier 01-10-2010 10:23 PM

Quote:

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.

GpsFrontier 01-23-2010 09:25 PM

2 Attachment(s)
I was looking for something else when I ran across these pictures of lettuce being grown in a system like yours, with the 1 inch cubes. I thought that 1 inch cubes might be kind of a small hole for the neck of the plant, though I would guess it would depend on the type you are growing. There are hundreds of variety's of lettuce.

Luches 01-24-2010 04:59 AM

Between the cup and the plug a morsel may drop ;)

smurf 01-24-2010 06:24 AM

Does any one know how close you can plant lettuce together in a water culture system? I am thinking of using this system to grow lettuce just because its ez for them and me.

Luches 01-24-2010 06:34 AM

On the picture I've posted it is 25cm, 12.5cm and only 5cm for the tiny seedlings

GpsFrontier 01-24-2010 07:28 AM

Quote:

Originally Posted by smurf (Post 3975)
Does any one know how close you can plant lettuce together in a water culture system? I am thinking of using this system to grow lettuce just because its ez for them and me.

That would depend on the type you were growing. You don't want them to be crowded, but you don't want to waste space either. How big does the variety you want to grow get? Then space them that far apart, maybe just under that. They wont mind touching there neighbors, as long as they have elbow room.

Luches 01-24-2010 08:10 AM

Commercial type of lettuce doesn't vary that much in size and hence gullies are often pre-drilled to a standard size. You have to settle for some kind of standard size somehow, as you can't change the space next season when changing varieties - or can you? Well, you can always try :)
In case you have a bigger variety, and it's getting narrow, you can always harvest earlier.

Actually I've ordered a new type of gully which has an open top (has removable cover). The cover is made from some Styrofoam and can in fact be changed easily. And, different spaces can hence be used. Also the gullies are much easier to clean with this type of removable top.

In commercial system you ALWAYS have several runs of differently spaced holes for different growing sizes (like shown on my pictures). There is a rotation and the seedlings grown in special nurseries will be moved to smaller spaced runs first, eventually to a larger spaced- or directly to the final, wider spaced gullies.

If running a smaller or medium scaled setup and intending to rotate production, one might even consider having one half spaced run for a pair (2) standard spaced. It is certainly worth a thought!

Amigatec 01-24-2010 09:49 AM

I have grown them very close together in a DWC and a E&F. I grow mostly looseleaf, and have had good luck.

smurf 01-24-2010 05:50 PM

well my goal is to run a troff system. I am thinking about 32'l x 4'w and about 2' deep unless i need it deeper? I hope not. I have the foam to support them, and i want to grow romaine lettuce as it is my favorite lettuce.

GpsFrontier 01-24-2010 06:27 PM

1 Attachment(s)
Quote:

Originally Posted by smurf (Post 3984)
well my goal is to run a troff system. I am thinking about 32'l x 4'w and about 2' deep unless i need it deeper? I hope not. I have the foam to support them, and i want to grow romaine lettuce as it is my favorite lettuce.

4 inches or feet? Feet wide would should work fine but Romain is kind of a large taller plant and would likely tip over if not supported well. I'm not positive but I think this image is of Romain (it looks like it). In stores they usually just sell the harts of the plant, and take off the large outer leaves. It looks like the foam is 2 to 3 inches thick and supports them well.

Luches 01-24-2010 10:08 PM

The picture is impressive, but this isn't romaine lettuce, not even any other lettuce - no way. Although it's called so at the blog the picture provides from. That looks much more like over matured Pak Choi or some other related chinese kale type. Btw: look at the hand at the left, not at the head of the guy, that gives you a better proportion of the size.

Romaine lettuce can be grown under the very same conditions and setups as other lettuce types. As I said earlier, if some type grows a bit to big - simply harvest earlier. It's more delicious and has higher nutritive value at an earlier stage anyways.

One Foot (1') is standard an deep enough for lettuce in Deep Water Culture.

GpsFrontier 01-25-2010 03:06 AM

Quote:

The picture is impressive, but this isn't romaine lettuce, not even any other lettuce - no way.
I have never grown Romain but as I mentioned, I thought it was Romain because it looks like it to me. Is it Romain or not Romain is not the question. The point was that they were taller plants and would be a bit top heavy and would probably fall over in a 4 inch wide trough, if that was what was planed. Even though 4' does mean 4 feet, I wasn't sure if that is what was meant and just wanted to clarify.

Yes, if you look at the hands (what I did) will give you an idea how tall they are. I would guess about a foot. Going by my hands the Styrofoam would be 3 inches thick. The plants are a good 4 to 5 times that, and that would put them at about a foot+ tall. That also makes it about twice the height of most lettuce I have seen growing (like the ones in the images Luches posted). The Romain I get at our grocery store is around a foot tall in height. So whatever it is in the picture, it should be a good compassion.
Quote:

Although it's called so at the blog the picture provides from.
I have no idea where the image originates from, or what they say the plants are. Also the reason I did not say it was Romain for sure. I have compiled hundreds of similar pictures, and stored them in a file on my computer. I simply do a search for hydroponic plants or what ever I am looking for, using the image search feature from Yahoo, Google and Bing (formally known as MSN). Then save the image to my computer, they don't come with titles or URL's.

It's my understanding that Smurf wants to be able to sell this produce at the local farmers market. Not sure he wants to go to the trouble of building the systems to grow the produce in, only to need to harvest it early because they were too close together. The produce tends to look smaller to the customers that way and they feel like they are not getting their money's worth. You can always cut the price but then you cut your profits. I personally don't see much point in doing that. I would want my customers to feel like there getting a good deal. But at the same time I need to make enough back to cover costs, and also make it worthwhile for all my work.

Luches 01-25-2010 05:41 AM

When sales of hot chocolate go up, street crime drops.:)

Sorry, I have got no time and no patience for any such discussion that always focusses on individual points and hence drifts away from the little objectivity and common-sense that can be expected from such exchange. Unfortunately, there simply isn't a common-sense answer for many questions, but that doesn't mean that one shouldn't at least try to aim for it. And yet, kale is kale and lettuce is lettuce and if there is no point to that difference I don't know where it is.

I've given all needed information so far. If there are more questions, feel free to ask.

smurf 01-25-2010 06:18 AM

Thanks for your help guys ...
Yes i am talking feet not inches thats why i put one ' and not two. I have a great spot for this setup, and wont cost a lot for this system. As i have the foam for it already and the troff wont cost much to build at all. Thanks.

Luches 01-25-2010 06:28 AM

Quote:

Originally Posted by smurf (Post 3996)
Thanks for your help guys ...
Yes i am talking feet not inches thats why i put one ' and not two.

Of course you were talking inches, ehmmm foot - and it was clear and obvious to me. Even though I am not that familiar with US-units, I knew that ' means foot and nothing else ;)
You're welcome.

GpsFrontier 01-25-2010 06:57 AM

Quote:

Sorry, I have got no time and no patience for any such discussion that always focusses on individual points
Except for your own as always. And yet, you always prove you do have the time.
Quote:

Unfortunately, there simply isn't a common-sense answer for many questions, but that doesn't mean that one shouldn't at least try to aim for it.
If only you could.
Quote:

And yet, kale is kale and lettuce is lettuce and if there is no point to that difference I don't know where it is.
As usual of coarse.


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