If you are using this method for your tomatoes and peppers due to problems in the soil, you might want to try SIPs, or self irrigated planters. As imafan noted, they are easier, and I second this - a lady in FL, who has to plant all of her tomatoes and many other things in Earthboxes, due to nematodes and many other pests, got me hooked on them last season when she posted a link to a sale. I bought 3, and the rest is history! LOL I also found a site from imafan, showing how to build them, large ones, as well as out of buckets. Here's my album, showing many of the things growing in them, and the early part of the album shows them being built,
https://s24.photobucket.com/user/pepperh ... 20homemade
And here's about the best photo of the buckets with tomatoes, after only 5 weeks after transplant:
I grow herbs in hydroponics, but not flowering plants. As others have noted, they are much more difficult, due to having to change the nutrients for growth, blooms, and the fruit development, and they do suck up water! Like others, I can't imagine keeping a bucket of nutrients with no aeration, even though it obviously is done, otherwise there wouldn't be a name for the method! I keep a powerhead with a sponge filter (things I got from my aquariums) in my deepwater systems, as well as an airstone, but these are indoors, while yours are outside, which is why I figure you are using that method.
The SIPs cost more to set up, but once they are going, they are easy to maintain, as long as you have something to water them! The water is wicked up into the growing chamber from a reservoir below, through a soil-less mix, such as Pro Mix, into which some dolomite is added, to hopefully prevent BER in tomatoes. A trench of fertilizer is added, and this is slowly released over the summer - I used some fertilizer "socks" so they could be easily removed at the end. On the Earthbox forum I learned some tricks, one of which is to add 1 tsp of calcium nitrate to each box (these are equivalent to three 5 gal buckets) once a week, as a "snack". I have also added some of my hydroponics supplements, which seemed to help, for sure.
The homemade boxes are actually better than the originals, because the reservoir can be made larger. Mine are about double, so they do not dry out quickly. Cucumbers were the only ones that drained the originals, so I'll use just the homemade ones for them. Earthbox sells an automatic watering system (AWS), but I just use a drip system on a timer, which I tweak, by adjusting the time, and using different emitters, depending on how "thirsty" the plants are.
The plants in these things produced so much this season that I have already decided to reduce the numbers of many of the plants, as well as spacing them farther apart - the cherry tomatoes, especially, were so compacted that I could hardly find many of them!
Though this will only be my 3rd year coming up, others out there say that the mix used in the containers can be used many times - some saying they are on their 8th year, with no problems!