Backyard Aquaponics
A place to discuss aquaponics

Needed...
-nutrients - fish poo
-minerals - seasol / maxicrop

Ideal...
-pH - 6 - 7.6
-temperature - 15 - 25 c
-lighting - Dappled sun + part shade
-watering amount - well drained, no long flood periods.

Dunno, but cos is doing great in my flood and drain system, with nothing special. in my driveway, north south facing, full sun between 10 and 2. Sun is otherwise occluded by my neighbour's house or mine. Bed is against the western wall, so more morning than afternoon sun. I use nothing that the fish, and scoria doesn't provide.
hope this helps?

+1 on the scoria. no iron probs for me

lettuce require nitrogen and water. Insufficient water makes them bitter as does a long growing period. Let one go to seed, preferably a superior looking one. Sprinkle the dried seed head over the growbed media and oh oh chongo you have the next crop. Seed select has a multitude of varieties of heritage seed types.