Jaden:

Lettuce is fine. My Apple snails love Spinach. I feed them celery and
carrot too. (I'm convinced that carrot does wonders for their shell
colour).

I'm not sure if it matters but I think my snails are probably ramshorn.
Whatever they are they don't like carrots, spinach, clover, grass nor
yellow squash. I think I have spoiled them on iceberg lettuce; they won't
even eat romaine!

--
Mac Cool