Johnny all the things you mentioned in your post can potentially be used to fertilize orchids, but I am afraid none of them can be used in your set up. The semi hydro set up that you use can only be fertilized with inorganic water soluble fertilizers. All the sources you have mentioned are organic complex substances. they need to be broken down by bacteria into inorganic substances for the plants to be able to absorb them. In your Sh set up this will cause fouling of the water and eventually rotting of the roots and ultimately the death of your plant. I would rather use the agricultural fertilizers. Just make sure that they are water soluble better if meant for foliar applications and that the Nitrogen is in the form of Nitrate (NO3-) pr Ammoniacal (NH4+) and not completely Urea. Most fertilizers will have a blend of all three. And if that is also not possible. the easiest house hold available material that you could use is urine. It sounds crazy and disgusting for us but for plants it is simply a great source of nitrogen, vitamins and potassium. It is a bit low on phosphorus though. Just dilute the urine 1:15 with water and that should work well as a fertilizer solution.