Here's a link to a very informative thread.

http://forums2.gardenweb.com/forums/load/contain/msg0808395618861.html

I have used smart pots for tomatoes, cucumbers and several other vegetables for four years and love them. I haven't had problems with blossom end rot or other things like you describe. I suspect your problems are more likely caused by other things, primarily the variety you are growing or the potting mix.

Search BER on GardenWeb and you will find that some varieties, like many paste tomatoes, are most susceptible. Uneven watering that affects cacium uptake is another cause. As for cucumbers, I finally overcame many problems when I started growing Diva, a variety that is resistant to cucumber beetles and the many diseases they spread.

The next most likely cause of your problems is the soil mix. For the first three years I used smart pots, I used a mix of 70% soilless professional mix (Promix, Metromix or Fafard) and 30% compost. I only used organic fertilizers. My results were mostly good, but my plants suffered when we had a lot of rain in the early weeks because the soil held too much moisture when the roots didn't fill the pots.

This year, I discovered Al's 5-1-1 mix and filled all my smart pots with a modified version of that. Since they sit directly on the ground, Al told me they are more like miniraised beds than traditional containers. My mix is five parts pine bark fines, and one part each of peat, compost and Turface. I also added one tablespoon per gallon of agricultural lime (which helps with preventing BER) and one tablespoon per gallon of Osmocote Plus with trace elements. (Al also convinced me that organic fertilizers don't work as well in containers as they do in soil.) This mix held up very well to lots of rain in June and recordbreaking heat in July. Its also significantly cheaper than bagged soil. My tomatoes and cucumbers have done very well in spite of the usual insects and diseases.

The final source of problems is those insects and diseases. I have been much more aggressive in responding to problems this year than in the past, and it shows. I do stick to organic pesticides, like neem and spinosad. I've had the best gardening ever thanks to Al and all the other great folks who share their experiences on Gardenweb.

THANKS for ALL the INPUT!!! 2 questions-- what kind of Turface does Ohiofem use and does it make any difference whether the pots sit on ground, or foam slab on plastic? Mine are on ground in front yard, and foam/plastic on deck-- does Al's mix come ready-made or make-your-own? I seems like I was watering once or often twice a day with a shower-head attachment,(just at the base) so I don't know how it would have caused uneven watering. Thanks again! Also the thread was a GREAT source of info-- I sew, so there are future possibilities thx to you edweather!

Uneven watering is usually used to refer to plants that get very dry, then flooded. The moisture level varies wildly and often.

Al is tapla on Garden Web. I'll add a link below to one of his discussions of the mix, which unfortunately you have to make yourself. There are two mixes, and 5-1-1 is the one that works best for veggies and annuals. Classic 5-1-1 is five parts pine bark, and one part each of sphagnum peat moss and perlite. That's the one you want for containers that are not in contact with the ground. The Turface I used increases water retention so you wouldnt want to use it in 5-1-1 for smart pots that arent in direct contact with the ground. The Turface Al recommends is MVP, sold by landscapers and some sports stores to be used on athletic fields. If you read the whole thread below, you'll learn about alternative ingredients.

Here is a link that might be useful: Container soils -- water movement and retention