I have been doing research, trying to find grains that I can grow in the summer, as our temps get up to 80F in the house most of the time. I am growing wheat fodder in the winter, and I have done it for the past few winters.
I just got a small (8 watt) pump and timer to water my trays automatically. Pump and timer were $30, so I'm now up to $50 for my system, or 2.5 bags of rabbit pellets. My basic system without the pump has paid that several times over, as I have 12 adult rabbits and 36 growers at any one time (plus poultry, pigs, goats, etc)
Here in Mexico, I discovered, they grow corn, instead of wheat or barley for hydro fodder. Some operations even grow it to 12 days, giving nutrients after the 8th day, to get even more growth out of it (looks to be about 1 ft tall).
If you can read spanish (or you could use Google Translate), do a web search for "forraje verde hidroponico" (hydroponic green forage). The spanish word for corn is "maiz". Lots of systems throughout Mexico, though none in my area, which is kinda strange, as we are the cattle and dairy capital of Mexico.
Corn likes 70-75 for germination, 80+ for growing. That should be doable for me! The resulting fodder is a bit lower in protein than wheat (around 13-14%), but would still be worth it, if you fed with a higher quality hay. This is an alternative to those of us that need something for the summer.
I did find some spanish research papers on feeding corn fodder vs pellets for rabbits. On nearly all of them, fodder+minerals gain weight faster than the control group (pellets)
