Update. It has been just shy of 3 weeks. I lost a few peppers, but I expected to lose a few as I learned the ins and outs of hydroponics. The tomatoes are growing like weeds, and I'm starting to train them, so I can hopefully grow them in a screen of green style trellis. The second picture is a close-up of one of my Cherokee Purple tomato plants. A few of the leaves are starting to turn brown. Any idea what this might be? I water/feed all of the plants on the same schedule, and I'm not seeing it on any of the other toms.

The wilting at the top can indicate a few different things. Water is the most likely. However, there are lots of things that cause a plant to not take or keep water. One is the heat mentioned. However, the leaves don't have the distortion that I've seen on plants too close to lights. I think grizzman was definitely on to something with the second bullet in his post above. If the plant gets big enough to not be able to take up enough water to keep up with evaporation you experience results very similar to those above. With ground plants, that is commonly from nematodes or a root disease. With hydro it can be from fertilizer build up. In that case, flush for a couple days really well. Then resume feeding. Or, as was stated, if not all the roots are getting what they need then neither will the rest of the plant. There is also pH of the medium, but with regular drip systems that isn't so much of a concern as the solution helps regulate that enough to at least keep the plant going. Maybe not optimum, but not unhealthy either. Root rot can obviously be a concern. Particularly in the type of containers you are using. Flush one of them good and smell the water. If it's foul, you might have a problem. You can try a little peroxide if that is the case. By a little I mean a few teaspoons per gallon of water max. It's like radiation for plants. Radiation is bad for us. Peroxide is bad for roots. But if something else is killing you, it's better to get sick from radiation and survive. The peroxide will damage roots, but can also kill bad microbes. Hopefully the plant will heal. I'd only do it if you know there is a root disease. I use DWC with a bubbler ring (DIY hydrofarm). I also use ebb and flow. This was my first year with ebb and flow and peppers. Outstanding results. I am thinking of selling all my DWC stuff. With peppers, this was my best year ever and it was solely because of my ebb and flow system. I wish I would have tried that sooner.

The equipment is expensive compared to containers and soil but will last for many seasons. The work is much different from soil. Much of the work is setting up your system and mixing up nutrients. If you have a large enough reservoir you can go for a week or longer before adding water and nutrients. The more you spend on equipment, monitors and timers, the easier it gets. It's hard to justify the expenses compared to soil, but ultimately you can save time, space, and water. One major difference vs. soil is that there is less of a buffer for mistakes. Overfeeding, wrong pH, res running dry, etc... All these things will kill hydro plants very quickly. Soil can suffer a drought and still come back. Depending on the hydro system, it may also be difficult to grow a variety of different peppers. If you want the best tasting harvest you will need to flush with plain pH'd water first, this is harder to do if you have other plants in the system that aren't yet ready. In any case, although it's more complicated and expensive it's becoming more common. In a limited space, hydro will produce much more fruit with less mess. Last year I had 3 peppers and 1 basil plant in individual 5 gallon "bubble buckets". They peppers were huge and outgrew the system before harvest. I learned that I was feeding them too much nitrogen, and I needed a larger reservoir, and a better system for adding water and nutrients. This year I'll be using a drip system with at least 20 peppers in coco coir. For a setup like this you need a reservoir, pump, tray, containers and coco coir. The hydroponics forum on this site is full of information, and google helps with anything else. Be aware that most of what you will find is not about growing peppers, but the system is what's important. I like to build and experiment, so I haven't gone with a packaged system. If you have the money to spend, there are some great looking systems out there. If I was starting from scratch and wanted to be up and running ASAP there is a system called the Eurogrower that looks very good. The cheapest diy system is probably "bubble buckets" or DWC. You can do this with buckets or a rubbermaid container, air pump + stone, net pots and hydroton. Google "DWC" and you will find everything you need to build your own. Hope this helps, I'm just a beginner, but I've done a bit of research. Honestly though, If I had the space then I'd prefer large containers of quality soil + drip irrigation.

I am doing something similar but with a two cup method. the inner cup has plant, roots, potting soil, and perlite added. the bottom of the cup has a bunch of holes for the roots to grow out of and for the water to drain. I put that cup into another cup that has my nutrient solution in it. The roots will extend out of the inner cup and fill the outer cup.