on picture 27 from your link. the brown edges are very indicative of too strong a solution. I don't grow lettuces, but I thought they were supposed to be grown in the 400-500 ppm range.
What do the tomato leaves look like? my first thought was spider mites. the stem curl could be a virus or it could be too much nitrogen.

Thank very much for your reply. I was thinking the solution strength was too much as well. I will be running a pure water solution for 24 hours and will then then switch back to nutrients. I had originally been running about 1000 ppm for the lettuce but reduced it to 700ish. This may still just be slightly too much though. I have seen some suggestions that the cause could be calcium deficiency but this seems unlikely since many of the heads are doing great.

The tomato leaves look wilted at first and then they start turning very tough in texture before they just turn brown and die. Some of the stems also have a brown looking color in certain areas. Take a look here.

http://picasaweb.google.com/hydroscotty09/TomatoLeaves?authkey=Gv1sRgCK6j45ib-LyqLw#5378175743879608674

I am also running a water only solution for 24 hours and will introduce nutrients again tomorrow.

Here is a link that might be useful: Tomato leaves

You mentioned that some of the stems have random brown marks on them...

This is characteristic of late blight and is nasty. It will ultimately kill your tomato plant and rapidly infect any other tomato plants you have nearby.

I sincerely hope you don't have this, I lost all my toms to late blight this year, gutted!

This website may help you: http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomWlt/TomWiltKey.html

And also here: http://aggie-horticulture.tamu.edu/publications/tomatoproblemsolver/stem/late_blight.html

You mentioned that some of the stems have random brown marks on them...

This is characteristic of late blight and is nasty. It will ultimately kill your tomato plant and rapidly infect any other tomato plants you have nearby.

I sincerely hope you don't have this, I lost all my toms to late blight this year, gutted!

This website may help you: http://vegetablemdonline.ppath.cornell.edu/DiagnosticKeys/TomWlt/TomWiltKey.html

And also here: http://aggie-horticulture.tamu.edu/publications/tomatoproblemsolver/stem/late_blight.html

As for the lettuce, I grow mine in DWC and the raft type system, I don't let the EC go above 1.4 and keep the pH at 6.0

I'm with grizzman, sounds like too much nute for the lettuce, I've had good luck with bibb too. I too have over nute'd them, the browning along the edge is symptomatic of that.

As for the tomatos, I also agree with grizzman, but the nitrogen theory. When I was just learning, I charged my plants with ALOT of nitrogen, the stems curled like no other, spiral patterns, but exaggerated ones. leathery leaves is also a symptom of too much nitrogen. but the older leaves on my tom's, even when healthy, turn leatheryish and curl/yellow.

Look into too much ethylene caused by too much nute, its the over prod of ethylene that causes the stem curl.

Good luck

I have been running the tomatoes with about 1,200 - 1,500 ppm so I'll back down with the new nutes. I'm not sure how to reduce the nitrogen without impacting other key ingredients. I'll cut back on the boost though and see how this works. I do think I am seeing general improvement across all the plants since I ran the 24 hour water only to flush the systems.

I am hoping overall lower nutes will solve all the issues I am having.

Thanks to all and I'll post back if this solved the issues.

I grew mt toms this year at 800-1000 ppm and they grew great. see if your nutrient supplier has a calculator available you can tinker with that'll allow you to adjust your solution to have less nitrogen while maintaining a decent potassium level . later you'll need to find a way to increase the phosphorus levels (for fruiting).

Hey everyone -

OK. I have reduced everything substantially and have seen zero success here. In fact, the included pictures for today just occurred over the last day or so after I had reduced the nutes to 400 for the lettuce. This happened on the Romaine and is starting to appear on the little gem. The Romaine is horrible looking with its fresh defects which indicates to me that the change is having very little affect. One comment is that I am having a horrible time maintaining the pH. It kept dropping to 5.2 - 5.4 and then suddenly swung up to 6.6 today.

The interesting part about the lettuce leaf is its curling inward everytime prior to turning brown on the tips.

The water I am using is both RO and DI so I am wondering if the DI is contributing.

The tomato is not improving and looks much worse after lowering the nitrogen and total ppm.

I know it is soon, but these changes are dramatic enough that it tells me I am headed in the wrong direction.

I am obviously missing something here so all help is appreciated.

My pictures are attached.

Thanks to all.

Here is a link that might be useful: Lettuce and tomato pics

What is DI water?
Also, remember it's only been two days. when I had a nutrient deficiency, it took the better part of two weeks for the symptoms to disappear. I'm not suggesting you wait that long. two weeks could be the end of a crop.
Other thoughts:
Remember the existing tip burn will not go away. Is tip burn continuing to develop on new leaves? you can cut off the brown and see if the new edge browns out as well.
one of your pictures showed a white fungus/mold growing in a lettuce head. what was different about that plant than the others around it?
how are your plants being held in your NFT runs? I could tell from the pictures they were in smallish squares, but couldn't really tell what (if any) medium they were in?
are the plants that are browning at the end, beginning, or middle of any particular run? are they located on the edge runs or in the middle runs?
basically looking for a physical pattern that could help point out a problem.

Hey gizzman -

I thought I had posted a response back a few days ago but don't see it here.

To answer a few of your questions -

DI is deionized water.

I don't think the issue is showing up on any of the new leaves but the heads it happened to appear to be permanently damaged. The center of the heads closed up and developed the same soft mushy texture from the leaves breaking down. The center leaves almost appear see through. The fungus in the one plant started to appear on one of the heads of romaine that had the worst tip burn. What is interesting is the white fuzz only appears inside the heads that close up. Maybe this closed off area is preventing air from getting in to dry out the area. Tip burn on the outer leaves just dried up and was easily removed as a dry edge.

I cut all of this edge browning out recently and will be waiting to see how the plants perform.

I am using a commercial style system that has 1" square holes punched into the top. I simply transplant 1" grodan starter cubes into this cutout.

The browning really appears to happen anywhere in the system so it is hard to pinpoint. The one thing I can say with confidence is that the browning is on the older plants only at this point. I have newer growth coming up now so the next 2 weeks will certainly be revealing. I am crossing my fingers.

Thanks for all the questions and suggestions. It is helping me look more closely at my system.

Hey everyone -

It has been 10 days now and I haven't seen any improvement. I even trimmed off the old problem areas and new leaves have taken the place of those with the same dead mushy tips. I have been running in the 375 - 480 ppm range with a pH between 5.8 and 6.3. Not sure what else to do so everything welcome.

Could temperature have anything to do with it? 80 F seems just fine. ??????

I'm not sure I can help you much further as my lettuce knowledge is very limited. from what I saw and what you describe, it appears the 'dead mushy' areas are too moist and thus promoting decay.
What do the roots look like?

Ok. Thanks for all your help. Roots look good to me. They are just slightly off-white but strong and thick.

I'll keep working on it to see where I end up. If anything comes to mind, please drop me a note.

Thanks

Just to let evryone know. Adjusting the pH up to 6.3 - 6.6 solved the issue. I had a low availability of a critical nutrient when running at the 5.8 - 6.2.

Thanks

hello, did you find out what nutrient was missing a ph 5.8-6.2?