I think you will be very pleased with the results from Maxsea fertilizer(s)
Maxsea is not totally 100% organic. Some of the nitrogen is derived from the typical Amn. Nit. form but it is loaded with many of the micro nutirents as well as sea weed.

I learnt about this fertilizer years ago when one of the most highly regarded ( due to their super healthy stock ) whole+retail nurseries in our area was using it as their prime fertilizer.
It's not cheap, but it sure is effective and I think you will see a marketable decrease in accumulative salt build up in you pots and your plants may not be pushed into early decline .

What nutrient combination to use should be based on what potting medium is being used, what the irrigation water is like. If both operations are using similar media and have other similarities in growing conditions, then the same product might be appropriate.

As with most organic conversions, you're going to want to start at the beginning, with composts in the potting mix. Aside from providing nutrients on its own, compost also contains the microorganisms necessary to free up the "boxed" organic fertilizers you might add later. The problem with making the transition is that you'll really not want to mix "blue waters" in, as they contain salts which can upset the soil flora.

I've been doing organic containers for a couple years, and they seem to work at least as well as the alternative. It's also cost effective if you're doing enough containers, as a yard of compost makes an awful lot of compost tea, which is IMO the best organic fertilizer.

Link below is for certified potting mixes, recipes start on page 15.

Here is a link that might be useful: organic potting mixes

Amiga -
If you are getting good results, don't change.

One "advantage" of most organics is that they are weaker, and therefore harder ot over-fertilize.

" I recently was approached by someone trying to get me to use organic fertilizer. " OK ... will he provide you with enough of the stuff, FREE, so you can run some side-by-side tests on a willing customer's plants?

Ditto what Organic Johnny said. In addition, worm castings are an excellent organic fertilizer for container plants. They are especially good for house plants, since they don't have an odor.

Sally

Speaking of worm castings...have you checked out TerraCycle Plant Food? It's essentially liquified worm castings in a spray bottle. It's actually packaged in bottles collected from schools and recycling centers. Been using it for quite some time after getting it from Home Depot (or Whole Foods, I can't remember). Nifty!

Here is a link that might be useful: TerraCycle

for container grown plants, I would look for fertilizer nutrient ratios, media selection, EC rating/pH based on flow through analysis; water analysis including alkalinity, crops under consideration,stage of development,container size;rootzone temperatures,spacing, and the growing environment...
I am not interested in lush growth but toning based upon balanced nutrition at a given stage of plant development so that perhaps I might position myself to limit pesticide use... there is a concept of luxury consumption
of a given nutrient causing competition and interference with the uptake of other nutrients. this can be found on the ncsu floriculture website and other university sites; page 21 of the USDA Handbook 674 (vol 4.) (Dr. Thomas Landis) and so forth