Well, after a little searching, I found some pertenant information that could be used by you. This is a post from a forum that I frequent alot. Jvision is the member I pulled this article from and he has well over 30 years experience in aquaculture. The post is geared towards a heavily planted tank that may contain a few fish but would be able to be used for hydroponic setup as the feeding schedule for the plants are outlined. just figure out the volume of water in your hydro system and use the corresponding schedule. Thanks again Jvision for all the reasearch you do.
All this being said, you must remember that this person is referring to a tank with a filtration system and a thick substrate (gravel bottom). Like I mentioned in my previous post, you will have to concern yourself of two things, ammonia and nitrate spikes which will occur in the first month or two with a new setup. Ammonia will burn gills and roots in high enough concentrations and in a barren system like a hydroponics resivoir it is very possible to occur. nitrate, while useful to plants is like CO to fish and can cause a rapid die off which in turn can cause a spike in ammonia levels.
I am assuming that you do not have any substrate in your resivoir where the fish are being housed so you really should create a centralised system to which all water returns to a tank with a filter, gravel, and even a few bunches of hygrophyllia, ludwigia, vallisneria, etc.
General Dosing Guideline for High Light and well planted aquariums. Macronutrients should be dosed on even days, and Micronutrients dosed on odd days.
10- 20 Gallon Aquariums
+/- 1/8 tsp KNO3 (N) 3x a week
+/- 1/32 tsp KH2PO4 (P) 3x a week
+/- 1/32 tsp K2SO4 (K) 3x a week
+/- 1/32 tsp (2ml) Trace Elements 3x a week
50% weekly water change
20-40 Gallon Aquariums
+/- ¼ tsp KN03 3x a week
+/- 1/16 tsp KH2P04 3x a week
+/- 1/16 tsp K2S04 3x a week
+/- 1/16 tsp (5ml) Trace Elements 3x a week
50% weekly water change
40-60 Gallon Aquariums
+/- 1/2 tsp KN03 3x a week
+/- 1/8 tsp KH2P04 3x a week
+/- 1/8 tsp K2S04 3x a week
+/- 1/8 (10ml) Trace Elements 3x a week
50% weekly water change
60 – 80 Gallon Aquariums
+/- 3/4 tsp KN03 3x a week
+/- 3/16 tsp KH2P04 3x a week
+/- 1/4 tsp K2S04 3x a week
+/- ¼ tsp (15ml) Trace 3x a week
50% weekly water change
100 - 125 Gallon Aquarium
+/- 1 1/2 tsp KN03 3x a week
+/- ½ tsp KH2P04 3x a week
+/- ½ tsp K2S04 3x a week
+/- ½ tsp (30ml) Trace 3x a week
50% weekly water change
EI target ranges
CO2 range 20-30 ppm
NO3 range 5-30 ppm
K+ range 10-30 ppm
PO4 range 1.0-2.0 ppm
Fe 0.2-0.5ppm or higher
GH range 3-5 degrees ~ 50ppm or higher
KH range 3-5