The swordtail you have might be the only one to really go after lettuce, but you never know, maybe the others will too. Use romaine lettuce, or raw spinach instead of regular iceberg lettuce. Pretty much any leafy green veggie will be fine except for iceberg. To make it softer and easier for the fish to eat, you could let it wilt out of the fridge for a while, or put it in the microwave for 30 seconds or so to wilt it. If you're not so good about keeping fresh veggies in the house, like me you could use little bits of frozen spinach. Just make sure you don't leave any veggies, fresh or frozen, in the tank for more than a few hours since it will cloud the water.
There is also a sticky, I think in the article section, that goes into feeding vegetables in general, it might give you some other food ideas, and different ways to do it :thm:
I put a small peice of romaine lettuce in and the fish dont seem to care. They weren't eaiting it. Then I put flakes in there to see if they were even hungry and they gobbles them up, lol. I still have the lettuce in there, when I go up to bed i'll take it out.
i fed shelled peas and lima beans that were extras from the birds yesterday, all the bottom feeders, even the smaller cichlids and angel fish went for them.