I started a
new project recently that might be of interest here, if people want to talk about it
An interesting project indeed. I had a go at hydroponics years ago, on one level
Off hand to get past those complicated issues like gravity you need a separate pump for each level. Or.. use one pump to raise the water to a reservoir of sorts and then feed each level by gravity from that source. You could use a float type of switch to keep the reservoir full..
My hydroponics project ended with the realization that Safeway was more dependable, cheaper and not as messy.