How about I just summarize the pros and cons for you?

Keep in mind that things change a bit when you use SWC where the non water soluble fert is mixed in with the growing media. I will explain why in a bit.

The primary disadvantage to organic fertilizers in containers is that they are not in a form plants can use immediately. They require biological processing before plants can use the nutrients. In the ground there are generally plenty of active organisms to do this work. Worms, fungi, bacteria, nematodes and more are all in the soil consuming and processing organic matter.

In a container these organisms are largely not present due to their being no soil and environmental conditions (temp/pH/moisture levels) fluctuating rapidly. This isn't to say there aren't bacteria present to do the job because there are, but not to the extent they would be in the ground along with other soil critters.

This makes it difficult to predict what nutrients will be made available and when as it depends on the soil critters in the soilless potting mix.

In a traditional, top watered container as the organisms make nutrients available they tend to run out the container when it is watered. So, even though the bacteria are doing their job the best they can, those liberated nutrients aren't going to last long before they are flushed out the drainage hole.

This makes using water soluble synthetics preferable as they are immediately available to the plants.

OK, now in SWC there are some differences. The first difference is that because they are bottom watered instead of top watered and there is no drainage hole per se, the nutrients that are liberated from the organic fert have no place to go. This makes them hang around waiting for plant uptake longer than they would in a traditional container.

The typical advice for organic ferts in SWC is to use 50% more than one would with a synthetic. It works.

It is questionable how well it works in cool weather such as when one might start peas or broccoli and other early season plants (the bacteria aren't particularly active in cool/cold conditions).

Does that help?

I didn't even read what he said, but I agree.

Al

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http://forums2.gardenweb.com/forums/load/contain/msg0210213311349.html

Here is a link that might be useful: More info if you click me

YES "justaguy" Thank You! That is exactly what I wanted to know and "tapla" that will keep me busy reading for quite a while. Again thank you both very much.