So you think the fish stuff would be ok this stage in flower?

Well, the Fish will encourage the beneficial fungi to take hold onto the barley and will select for the beneficial funguses while there is some cool chemistry with how the barley starts to suppress the bad fungus like mold and mildew. However, there is a caveat and that is if your ventilation is not proper the fish will help the mildew explode. It is really common for plants in this stage of flower to get mildew due to more water in the air from transpiration. So if the heavy humid air is not being controlled at 50%-70% than you can have problems depending on health of soil/plants. Lots of info on this regarding ponds and how the benifical fungus will digest the barley and hydrogen peroxide is produced as a result thus eliminating alge etc. A fun rabbit hole to dive into. The barley alone will probably be a safer bet and maybe try adding fish on next round.... Buildasoil has a great soy aminos hydrolysate or fish hydrolysate powder and can be foliar sprayed up to last 2 weeks of flower.

I bet your friend is super stoked you moved up there :)

Yes, him and I make a great team! We work together well!