@andrewdouglas Hi from Indiana USA Love those windows you have. Great PICS Mine window is just a small one now, but I hope to go to a larger one soon My plants show a definite iron deficiency (common in aquaponics) and I have not been able to fine chelated iron locally. If used sparingly and carefully it is suposed to be a help. Your roofgarden idea sounds wonderful and I am also hoping to be able to get a greenhouse up soon. I finally have started a journal to help remember my mistakes and successes. Happy windowfarming. Sylvia Manchester Indiana USA