Just a word of warning to be vigilant and not let it take over. Water lettuce can get massive, taking over and dominating your other floaters. I started with some small hitchhikers like yours and although they don't normally get more than 3-4" across (often smaller), for some reason they like my tank and I have several 8" ones. It makes it easy to control but like other floaters they can be pretty invasive if you let them.