What kind of lettuce? I'm playing around with growing veggies in large pots.

Romaine and iceberg. Romaine is a good way to start because it grows like mad. Plant 2 inches apart in a large pot. Then as it grows, thin it by eating the baby lettuces. Many of my vegetables are in large pots and it works well. I have moved to raised beds for radishes, parsley, dill, and lettuce. and chives. To combat bugs and critters. I put 4 habeneros in the food processor and process in to paste, mix with vinegar then spray with the hose to lightly cover the plants. You can add garlic as well. It even works on those pesky white aphid like flies