Well, Pirranah, I tried to post a similar question earlier today but it didn't post. I was looking at using vermicompost tea with fish emulsion.

If you enter "organic hydroponics" in the search engine, there are suggestions out there, including an interesting article from an old Mother Earth News article: http://www.motherearthnews.com/Organic-Gardening/1977-03-01/Organic-Hydroponics-A-Simple-Solution.aspx

On page 2 of that article, the author lists a suggested solution made with fish emulsion, compost tea and blood meal--maybe I'm leaving out one or two ingredients, so be sure to read the article.

I am interested in going this route too so let us both post our successes and failures in this area.

Connie

You should bear in mind that your proposed concoction does not contain the nutrients in the chemical form that allows the plants to absorb them through the roots.
The fish emulsion contains nitrogen in the form of protein. For this to become available to the plants, you require a bacterial breakdown process, ie: from protein to ureum to ammonia to nitrite and finally to . . nitrate.
That's not exactly what hydroponics is about.

There is however a lot of interest in finding natural resources (eg: woodash, dolomite, bonemeal and urine) to produce chemically acceptable nutrients.

How about beneficial microbes With products like em1 or recharge. They break down organic compounds into fertilizer.