Bubbler setup too hot
 

I have a bubbler setup running in a large tupperware container with tomatoes and some green beans. The green beans seem ok, but the tomatoes have started wilting today in the heat. It's very hot here (Denver) today and I'm not sure what to do about it. The plants have been growing amazingly over the last few weeks but since I drained the bubbler and replaced it with pure water (no nutrients) to flush out the salts in the plants temporarily, the roots have become slightly brownish and the tomatoes are wilting. Is it because of the heat? If so what can I do? If not the heat then what? Please help. I LOVE my tomatoes :)

Test the water temperature, you have classic singes of the nutrient temp being too high. The water/nutrient temp should be between 68 and 72 degrees. The attached picture is a picture of the roots of my strawberry plants last year, they were suffering from continues high nutrient temperatures. Wilting of the plants even though they have enough water is also another sign. Think of it like walking through the desert on a hot day and being able to drink all the water you want, only it's hot water. It wont bring down your core temp (refreshing), it will raise your core temp (heat exhaustion).

I can think of a few ways to cool the nutrient temp, some cost much money, some take constant attention, some take some work, and some money but don't take constant attention. The easiest and simplest is with ice, fill some 2 little bottles with water (almost full), let it freeze and stick the frozen bottles in the nutrient reservoir. This takes constant attention depending on how fast it heats up. Also insulating the reservoir from the outside heat can help keep the cool in (many different ways to do this). Also keep the reservoir out of the direct sunlight.

My 55 gallong drum
 

How do you think I should insulate my 55 gallon drum?

The water inside is chilled with an aquarium chiller, but I want to insulate it somehow. I'd rather not have something like the Pink Panther doing it.

He's itchy.

There are a lot of ways to do it, from as simple as warping it in bubble wrap, to building a insulated box to place it in. I don't really know what funds you have to work with, I also don't know what resources you have to work with. Personally If I wanted it above ground, I would build a insulating box. Not using Pink panther insulation, but lining the box with sheet Styrofoam (2 inch thick). That will give a good "R" value, and it's also water proof. I have designs in a pdf. that I would be happy to send anyone. You can also cool inside the box.

Where I live, I could build a good box for 1, 55 gallon drum and it would cost around $80. The sheets of wood and Styrofoam are 4 by 8 foot sheets. The 2 inch thick Styrofoam sheets are about $18 each and your likely to need two. Plus the OSB board (about $7 ea) to build the box, as well as the Styrofoam adhesive and 100% silicone to make it water proof. But for a quick fix you can probably get bubble wrap from UPS or other shipping places. As long as it's a "closed cell" material it will be a insulator. Just wrap it tightly many times, and keep it out of the sun. Don't forget the bottom, and the top. And if you could wrap a light blocking material around the final wrap, that should help also.

Yes try to check the temperature. i think if you slow it down before it goes to high then everything is gonna be better. i will try to find some more information about it.

cheers!!