Hello fellow green (or shades there-of) thumbs, I would like some feedback on the layout for these flood-and-drain style growbeds in a soon-to-be-built 20' greenhouse. Half, that's right, HALF of my current food budget goes to salads, so lettuce/cucumber/tomato are all very important for me.

Water will be pumped constantly from my ~1000 gallon rainbow trout pen which will also supply the nutrition. I've done some aquaponics in the past successfully, but this is my first stab at a larger setup and my first greenhouse, so all critique is welcomed.