Is this forum active any longer?

cbird,
It's just fall, the gardening forums go relatively quite for the winter.

I did SWCs for over a decade, tried organics fertilizer in them with ok but marginal results. The mix stays so wet in these that there isn't any microbial activity to break them down.

With a drip system you can get the same benefit of less watering if that is why you want a SIP.

Now I do use completely organics for my containers with nothing store bought. My blog outlines my mixes and fertilizer regime.

Here is a link that might be useful: Organic containers update

I went with a compromise and did Raybo's 3-2-1 mix and used 1/2 Happy Frog for the 3 portion. Seems like he has had success with that. I neglected to see that the recommended fertilizer strip in the Earthtainer construction docs recommend an organic fertilizer. I think with those two combinations I am good.